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Background: Carcinoembryonic Antigen (CEA) and 4-nitroquinoline-N-oxide (4-NQO) are cancer markers that play a crucial role in tumor risk assessment and early cancer diagnosis. Therefore, it is in demand to develop a fast, accurate, simple, and cost-effective method to detect these cancer markers for quick and early stage-cancer diagnosis and treatment., Results: Herein, we report a dual signaling approach for direct and indirect signal transduction of cancer biomarker binding on molecularly imprinted-electrodes integrated on an ePAD, enabling sensitive and selective quantitative analysis of 4-NQO and CEA. Multiple test zones on a single device based on artificial recognition sites using core-shell Cu-MOF@MIP were developed to create a selective "Dual-signal-ePAD". An effective and facile imprinting method on a Cu-MOF surface based on the synthesized of 4-VPBA/MAA/TRIM polymer. It resulted in a novel MIP useable as a high-performance sensing tool for the ultrasensitive and specific quantification of the target cancer biomarkers. Multiple tests consisted of voltammetric analysis of 4-NQO via oxidation of the analyte on a WE 1 , and impedance analysis of CEA via the molecular interaction with the imprinted WE 2 ., Significance: The proposed device provides enhanced electrochemical signal amplification due to its high conductivity, electrocatalytic activity, and the target-specific recognition sites for accurate determination of 4-NQO and CEA targets. The Dual-signal-ePAD exhibits good voltammetric and EIS response, oxidation currents of 4-NQO at -0.06 V and R CT of CEA, resulting in high selectivity and sensitivity with a linear response range covering the concentration range of clinical interest for both analytes. Dual-signal ePAD is a good candidate for clinical screening and POCT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Emtricitabine (FTC) is a commonly prescribed anti-human immunodeficiency virus (HIV) drug that has been classified as an emerging environmental pharmaceutical micropollutant due to its poor metabolism, refractory nature to wastewater treatment, continuous discharge with wastewater effluent and accumulation in the aquatic environment. Although there are no reported limits and toxicity of the drug in the environment yet, it is crucial to develop onsite, rapid, selective and ultrasensitive water sensing systems for FTC to ensure efficient risk management and environmental sustainability., Results: Herein, a molecularly imprinted poly(para-aminobenzoic acid) (MIP) was electrochemically prepared on iron oxide nanoparticles modified glassy carbon electrode (MIP/Fe 3 O 4 NPs/GCE) for selective detection of FTC using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). During the detection, the voltammetric signal of the MIP sensor decreased with increasing concentrations of the non-electroactive FTC, indicating hindrance of the MIP sensor's redox activity by the binding analyte. The sensor generated a calibration curve with a linear dynamic range of 1.24-24.7 μg L -1 and a limit of detection (LOD) and limit of quantification (LOQ) of 0.439 and 1.30 μg L -1 , respectively. Moreover, the MIP sensor was 5.2 times more sensitive than the control sensor, a non-imprinted polymer (NIP) sensor, and had a higher apparent binding affinity for FTC than the NIP sensor. The MIP/PABA-Fe 3 O 4 /GCE-based sensor achieved recoveries of 98.8 %-101.5 % for applications in real wastewater and drinking water samples., Significance: The combination of Fe 3 O 4 nanoparticles, electrically conducting polymer, and the MIP technology produced a novel, simple, cost-effective, and high-performance voltammetric MIP sensor for an anti-HIV drug, FTC. The result of this study shows that the sensor holds a significant promise for future onsite monitoring of emtricitabine in wastewater, pharmaceutical, and biological samples without prior sample pretreatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Catecholamines (CAs) are involved in a wide range of physiological and pathological processes in the body and are progressively being used as important biomarkers for a variety of diseases. It is of great significance for accurate quantification of CAs to the diagnosis and treatment of diseases. However, the separation of CAs from complex biological matrices is still a great challenge due to the trace levels of CAs and the limited selectivity of existing pretreatment methods., Results: In this work, a dual-recognition imprinted membrane (BA-MIM) was developed to utilize the synergistic action of pH-responsive boron affinity and molecular imprinted cavities for highly selective capture and release of CAs. The prepared BA-MIM possessed remarkable adsorption capacity (maximum capacity, 43.3 mg g -1 ), desirable surface hydrophilicity (46.2°), superior selectivity (IF = 6.2, α = 14.3), as well as favorable reusability (number of cycles, 6 times). On this basis, an integrated analytical method based on BA-MIM extraction combined with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was innovatively developed to highly selective separation, enrichment, and detection of CAs in rat brain tissue. Under the optimum conditions, a low quantitation limits (0.05-0.10 ng mL -1 ), wide linear range (10-1000 ng mL -1 ), good linearity (r 2  > 0.99), and satisfactory recoveries (88.5%-98.5 %) were obtained for CAs. The proven method was further applied to kidney-yang-deficiency-syndrome (KYDS) group rat model, revealed the intrinsic connection between kidney disease and catecholamine metabolism., Significance: This work provides an excellent reference paradigm for the effective construction of dual-recognition functional membrane material to the high-selective analysis of trace targets in complex matrices. Additionally, this integrated analytical strategy demonstrates its efficiency, sustainability, versatility, and convenience, showing remarkable prospect in a variety of applications for biological sample analysis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The present study elucidates the effectiveness of a molecularly imprinted polyacrylonitrile-imbued graphite-base electrode (MAN@G) for the selective detection of folic acid (FA) in food samples. The prime objective of the recognition and quantification of vitamin compounds like FA is the overall quality assessment of vegetables and fruits. The cost-effective, reproducible, and durable MAN@G electrode has been fabricated using acrylonitrile (AN) as the monomer and FA as the template over graphite-base. The characterization of the synthesized MAN@G electrode material has been accomplished by utilizing UV-visible (UV-vis) spectroscopy and scanning electron microscopy (SEM). A tri-electrode system based on differential pulse voltammetry (DPV) and cyclic voltammetry (CV) techniques was employed to explore the analytical performance of the synthesized electrode. Rigorous analyses divulged that a widespread linearity window could be exhibited by the electrode under an optimized experimental environment, ranging from 20 μM to 400 μM concentrations with an acceptable lower limit of detection (LOD) and limit of quantification (LOQ) of 18 nM, and 60 nM respectively. Additionally, this electrode exhibits high reproducibility, good stability, and high repeatability, with RSD values of 1.72 %, 1.32 %, and 1.19 %, respectively. The detection efficacy of the proposed electrode has been further examined in food extracts, namely orange, spinach, papaya, soybean, and cooked rice, which endorsed high accuracy compared to the high-performance liquid chromatography (HPLC) method. Moreover, the statistical results obtained from the t-test analysis were also satisfactory for the FA concentrations present in those five samples., Competing Interests: Declaration of competing interest The authors declare no financial or competitive interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Surface Plasmon Resonance (SPR) technology has revolutionized the study of affinity-based biomolecular interactions, offering label-free and real-time analysis capabilities. However, traditional SPR gold chips have been viewed as disposable due to challenges in post-use reconditioning, leading to significant resource wastage and increased costs. To address this issue, we propose a novel approach utilizing polynorepinephrine-based (PNE) Molecularly Imprinted Bio-Polymers (MIBPs) as alternative receptors to conventional antibodies. Self-adhesive MIBPs do not require covalent immobilization. This enables efficient and rapid chip functionalization and post-use removal, facilitating multiple reuses of the plasmon source without compromising analytical performance. We conducted a thorough characterization and data analysis, confirming the robustness and repeatability of a single MIBP-functionalized chip for human IgG detection. 10 cycles of reconditioning and reuse, assayed by 60 kinetic calibrations, were performed. Our findings demonstrate the potential indefinite reuse of SPR chips facilitated by PNE MIBPs, with implications for streamlining test development and routine implementation in SPR biosensing applications. Therefore, they represent a sustainable solution to the longstanding challenge of disposable SPR gold chips also by reducing the reliance on animal-derived Abs for bioanalytic testing. Being also extremely low-cost and green, PNE-based MIBPs minimize the ecological footprint associated with traditional SPR assays. Overall, our work represents a significant advancement towards the development of reusable SPR biosensors. It promises a more sustainable and cost-effective future for biomedical research and diagnostic applications, with application on other transducers and bioanalytical platforms., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Fluoroquinolones (FQs) are widely used for their excellent antimicrobial properties, yet their release into aquatic environments pose risks to ecosystems and public health. The accurate monitoring and analysis of FQs present challenges due to their low concentrations and the complex matrices found in actual environmental samples. To address the need for auto-pretreatment and on-line instrumental analysis, developing new microextraction materials and protocols is crucial. Such advancements will provide better analytical assurance for the effective extraction and determination of FQs at trace levels, which is of great significance to environmental protection and human health., Results: In this work, we presented a Co 2+ mediated paper-based molecularly imprinted polymer chip (CMC@Co-MIP), combined with UPLC analysis, to develop an effective analytical method for identifying and quantifying trace amounts of ciprofloxacin (CIP) and enrofloxacin (ENR) in water samples. Notably, the addition of Co 2+ in CMC@Co-MIP helped to capture the template molecule CIP through coordination before imprinting, which significantly improved the ordering of the imprinted cavities. CMC@Co-MIP exhibited a maximum adsorption capacity up to 500.20 mg g -1 with an imprinting factor of 4.12, surpassing previous reports by a significant margin. Furthermore, the enrichment mechanism was extensively analyzed by various characterization techniques. The developed method showed excellent repeatability and reproducibility (RSD < 13.0 %) with detection limits ranging from 0.15 to 0.21 μg L -1 and recoveries ranging from 64.9 % to 102.3 % in real spiked water samples., Significance: We developed a novel microextraction paper-based chip based on Co 2+ mediation, which effectively improved the selectivity and convenience of extracting FQs. This breakthrough allowed the chip to have a high enrichment efficiency as well as provide a robust on-line instrumental program. It also confirms that the imprinting scheme based on metal ion coordination is a high-performance strategy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A molecularly imprinting polymer (MIP) carrier with pH-responsivity was designed to construct a drug delivery system (DDS) focusing on controlled and sustainable capecitabine (CAPE) release. The pH-responsive characteristic was achieved by the functionalization of SiO 2 substrate with 4-formylphenylboronic acid, accompanied by the introduction of fluorescein isothiocyanate for the visualization of the intracellular localization of the nanocarrier. Experimental results indicated that CAPE was adsorbed onto the drug carrier with satisfactory encapsulation efficiency. The controlled release of CAPE was realized based on the break of borate ester bonds between -B(OH) 2 and cis -diols in the weakly acidic environment. Density functional theory computations were conducted to investigate the adsorption/release mechanism. Moreover, in vitro experiments confirmed the good biocompatibility and ideal inhibition efficiency of the developed DDS. The MIP can act as an eligible carrier and exhibits the great potential in practical applications for tumor treatment. A molecularly imprinting polymer drug carrier with pH-responsivity was designed to construct a drug delivery system (BFS@MIPs/CAPE) and applied in controlled/sustainable capecitabine release. [Display omitted] • A drug delivery system (DDS) was constructed based on a MIP carrier for controlled and sustainable release of CAPE. • PH-responsivity of MIP carrier was obtained by the functionalization of 4-FPBA. • Drug adsorption/release mechanisms of CAPE were investigated by density functional theory calculations. • Satisfactory results of the developed DDS illustrate the potential in practical application in tumor treatment. [ABSTRACT FROM AUTHOR]

Ofloxacin (OFL) is often abused in medicine and animal husbandry, which poses a great threat to human health and ecological environment. Therefore, it is necessary to establish efficient method to detect OFL. Electrochemical sensor has attracted widespread attention due to the advantages of low cost and fast response. However, most electrochemical sensors usually use one response signal to detect the target, which makes it sensitive to the variable background noise in the complex environment, resulting in low robustness and selectivity. The ratio detection mode and employing molecularly imprinted polymer (MIP) are two strategies to solve these problems. A novel molecular imprinting polymer-ratiometric electrochemical sensor (MIP-RECS) based on Fe-MOF-NH 2 /CNTs-NH 2 /MXene composite was prepared for the rapid and sensitive detection of OFL. The positively charged Fe-MOF-NH 2 and CNTs-NH 2 as interlayer spacers were introduced into the negatively charged MXene through a simple electrostatic self-assembly technique, which effectively prevented the agglomeration of MXene and increased the electrocatalytic activity. A glass carbon electrode was modified by the composite and a MIP film was electropolymerized on it using o -phenylenediamine and β-cyclodextrin as bifunctional monomers and OFL as template. Then a MIP-RECS was designed by adding dopamine (DA) into the electrolyte solution as internal reference, and OFL was quantified by the response current ratio of OFL to DA. The current ratio and the concentration of OFL displayed a satisfying linear relationship in the range of 0.1 μM–100 μM, with a limit of detection (LOD) of 13.2 nM. Combining molecular imprinting strategy and ratio strategy, the MIP-RECS has impressive selectivity compared with the non-imprinted polymer-RECS, and has better repeatability and reproducibility than non-ratiometric sensor. The MIP-RECS has high sensitivity and accuracy, which was applied for the detection of OFL in four different brands of milk and was verified by HPLC method with satisfactory results. A novel ratiometric electrochemical sensing platform combined with molecularly imprinted polymer and Fe-MOF-NH 2 /CNTs-NH 2 /MXene composite for efficient detection of ofloxacin. [Display omitted] • A Fe-MOF-NH 2 /CNT-NH 2 /MXene composite was prepared by hydrothermal method. • A MIP film was constructed by bifunctional monomer to improve the selectivity of detecting ofloxacin. • A ratiometric electrochemical sensor for ofloxacin with signal on/off mode was constructed. • The MIP-RECS has high selectivity, reproducibility and stability, and was verified by HPLC. [ABSTRACT FROM AUTHOR]

Fentanyl and its derivatives are a type of potent opioid analgesics, with the characteristics of diverse structure, high toxicity, extremely low content, and high fatality rate. Currently, they have become one of the most serious problems in international drug abuse control due to their extensive use in drug production and use. Therefore, the development of a rapid, sensitive, and accurate method for detecting trace fentanyl is of great significance. In this study, in view of its complex structure and trace concentration, a new molecular imprinting electrochemical sensor was developed through molecular simulations followed by experimental validation to detect trace fentanyl. The process consisted of first obtaining the optimal functional monomer and its molar ratio through molecular simulations. The recognition sites of fentanyl-imprinted polymers were predicted to guide the synthesis of imprinted membranes with precision approach to ensure an efficient and accurate reaction process. Reduced graphene oxide (ErGO) was then deposited on glassy carbon electrode surface by electrochemical reduction to yield large numbers of active sites suitable for catalyzing reactions of fentanyl piperidine for promoted efficient electron transfer and amplified sensitivity of the sensor. Accordingly, fentanyl molecularly imprinted film was formed through one-step electropolymerization to yield greatly improved sensing selectivity due to the specific recognition of molecularly imprinted polymer. Under optimal experimental conditions, the fentanyl sensor showed an extended detection range of 3.84 × 10−9 mol L−1–1.72 × 10−6 mol L−1 and a detection limit of 1.28 × 10−9 mol L−1. A distinctive feature of this sensor is its molecularly imprinted polymerized membrane, which offers excellent specific recognition, thereby boosting the sensor's selectivity. Throughout the sensor's development process, molecular simulations were employed to steer the synthesis of molecularly imprinted polymers and predict the recognition sites of fentanyl-imprinted polymers. The experimental outcomes proved to align with the simulation data. The final sensor exhibited outstanding selectivity, repeatability, stability, and high sensitivity. The sensor was effectively used to reliably track fentanyl in human serum samples, with acceptable analytical reliability, suggesting its potential for practical applications. A novel electrochemical sensor with enhanced sensitivity and selectivity for the detection of fentanyl has been developed. This sensor was fabricated using molecular imprinting technology that involved molecular simulations to optimize the functional monomers and their molar ratio, and experimental validation to produce the imprinted film. The sensor incorporates reduced graphene oxide (ErGO) as a catalyst for enhancing electron transfer and sensitivity. This sensor has excellent detection capabilities and low detection limit. [Display omitted] • A novel high-sensitive fentanyl molecularly imprinted electrochemical sensor was developed. • Molecular simulation accurately guides the synthesis of fentanyl molecularly imprinted membranes. • ErGO provides abundant reactive sites to catalyze the electrochemical reaction of fentanyl. • This sensor is applied to monitor fentanyl in real human serum samples. [ABSTRACT FROM AUTHOR]

Acteoside (ACT) was the main bioactive components in phenylethanoid glycosides of Cistanche tubulosa. Currently, the development of an efficient method for selectively separating ACT was crucial. Consequently, yolk-shell magnetic mesoporous carbon (YSMMC) was synthesized as a nanofiller to prepare molecularly imprinted membranes (ACT-MIMs) with instant noodles-like structure for selectively separating ACT. The numerous YSMMC were moved to the upper surface of ACT-MIMs by magnetic guidance and constructed the instant noodles-like structure in ACT-MIMs. The instant noodle-like structure increased the surface roughness of ACT-MIMs, which was conducive to improving the effective imprinted interface, increasing the selectivity of ACT-MIMs. In addition, the instant noodle-like structure had dendritic interleaved pathways in ACT-MIMs. The dendritic interleaved pathways can intercept ACT through ACT-MIMs, enhancing the permselectivity of ACT-MIMs. The prepared YSMMC possessed the dendritic shell and interlayer cavity structure can provide a great accommodation space, improving the rebinding capacities of ACT-MIMs. The high permselectivity (14.49), remarkable selectivity (7.52), and excellent rebinding capacity (120.48 mg/g) were achieved for the prepared ACT-MIMs. Thus, the design of ACT-MIMs with the instant noodles-like structure were valuable for selectively separating of bioactive components., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Monitoring the levels of L-Tryptophan (L-Trp) in body fluids is crucial due to its significant role in metabolism and protein synthesis, which ultimately affects neurological health. Herein, we have developed a novel magneto-responsive electrochemical enantioselective sensor for the recognition of L-Trp based on oriented biochar derived from Loofah, Fe 3 O 4 nanoparticles, and molecularly imprinted polydopamine (MIPDA) in xanthan hydrogel. The successful synthesis of these materials has been confirmed through physicochemical and electrochemical characterization. Various operational factors such as pH, response time, loading sample volume, and loading of active materials were optimized. As a result, the sensor exhibited an affordable linear range of 1.0-60.0 μM, with a desirable limit of detection of 0.44 μM. Furthermore, the proposed electrochemical sensor demonstrated good reproducibility and desirable selectivity for the determination of L-Trp, making it suitable for analyzing L-Trp levels in human plasma and serum samples. The development presented offers an appealing, easily accessible, and efficient strategy. It utilizes xanthan hydrogel to improve mass transfer and adhesion, biochar-stabilized Fe 3 O 4 to facilitate magnetic orientation and accelerate mass transfer and sensitivity, and polydopamine MIP to enhance selectivity. This approach enables on-site evaluation of L-Trp levels, which holds significant value for healthcare monitoring and early detection of related conditions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Methylparaben (MP), a commonly used antibacterial preservative, is widely used in personal care products, foods, and pharmaceuticals. MP and its metabolites are easy to enter the water environment, and their exposure and accumulation have negative effects on the ecological environment and human health, and have endocrine disrupting activity and potential physiological toxicity. It is still the primary issue of environmental analysis and ecological risk assessment to develop simple and reliable methods for simultaneous sensitive detection of these compounds in environmental water., Results: In this paper, a flexible molecularly imprinted fiber array strategy is proposed for simultaneous enrichment and detection of trace MP and its four main metabolites. The experimental results showed that the three-fiber imprinted fiber array constructed by MP imprinted fiber had the best effect on the simultaneous enrichment of these five target analytes. The enrichment capacity of the imprinted fiber array was 214-456 times, 314-1201 times and 38-685 times that of commercial PA, PDMS and PDMS/DVB fiber arrays, respectively. The limit of detection (LOD) of this method was 0.033 μg L -1 . The spiked recovery rate was 86.78-113.96 %, and RSD was less than 9.17 %. In addition, this molecularly imprinted SPME fiber array has good stability, long service life and can be used repeatedly at least 100 times., Significance: This molecularly imprinted fiber array strategy can flexibly assemble different molecularly imprinted SPME fibers together, effectively improve the enrichment ability and detection sensitivity, and achieve simultaneous selective enrichment and detection of several analytes. This is an easy, efficient and reliable method for monitoring several trace analytes simultaneously in intricate environmental matrices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Erythromycin (Ery) is a commonly used antibiotic that can be found ubiquitously in water bodies. The increasing apprehension over the adverse effects of antibiotic remnants in aquatic environments necessitates the prompt advancement of erythromycin detection techniques that are both highly sensitive and compact. Here, we propose a non-enzyme Ery sensor that integrates a mesoporous SiO 2 -based low-voltage oxide electric-double-layer transistor (EDLT) with a molecular imprinting technique, featuring a molecularly imprinted polymers (MIP) functionalized gate electrode. The mesoporous SiO 2 -based oxide transistor exhibits excellent electrical characteristics, including an operating voltage of small than 1.0 V, an on/off ratio exceeding 106 and a mobility of 14.95 cm2V−1s−1. At an ultra-low operating voltage within 0.5 V, the sensor exhibits a linear response to the concentration range of 1 nM–10 μM of Ery, with a detection limit of 0.22 nM and a sensitivity of 23.3 mV dec−1. Besides, the single-spike dynamic sensing mode effectively reduces the power consumption of the detection. The proposed sensor provides a rapid and convenient approach to detect Ery in aqueous environments, with benefits such as miniaturization, high sensitivity, and simplicity. Schematic of the fabricated Ery EDLT sensor and the sensitivity of the device to Ery at concentrations of 1 nM–10 μM. [Display omitted] • An EDL transistor erythromycin sensor based on molecularly imprinted polymers. • Ultra-low operating voltage within 0.5 V. • Single-spike dynamic sensing detection with ultra-low power consumption. • With a detection limit of 0.22 nM and a sensitivity of 23.3 mV dec−1. [ABSTRACT FROM AUTHOR]

Molecular imprinting polymers (MIPs) are synthetic receptors as biomimetic materials for various applications ranging from sensing to separation and catalysis. However, currently existing MIPs are stuck to some of the issues including the longer preparation steps and poor performance. In this report, a facile and one-pot strategy by integrating the in-situ growth of magnetic nanoparticles and reversed phase microemulsion oriented molecularly imprinting strategy to develop magnetic molecular imprinted nanocomposites was proposed. Through self-assembling of the template, it brought up highly ordered and uniform arrangement of the imprinting structure, which offered faster adsorption kinetic as adsorption equilibrium was achived within 15 min, higher adsorption capacity (Q max = 48.78 ± 1.54 μmol/g) and high affinity (K d = 127.63 ± 9.66 μM) toward paradigm molecule-adenosine monophosphate (AMP) compared to the conventional bulk imprinting. The developed MIPs offered better affinity and superior specificity which allowed the specific enrichment toward targeted phosphorylated peptides from complex samples containing 100-fold more abundant interfering peptides. Interestingly, different types of MIPs can be developed which could targetly enrich the specific phosphorylated peptides for mass spectrometry analysis by simply switching the templates, and this strategy also successfully achieved imprinting of macromolecular peptides. Collectively, the approach showed broad applicability to target specific enrichment from metabolites to phosphorylated peptides and providing an alternative choice for selective recognition and analysis from complex biological systems. • One-pot oriented molecular imprinting strategy was developed with reversed phase microemulsion system. • Improved binding performance was achieved than commonly used bulk imprinting system. • Functional monomers were explored toward cis-diol and phosphate groups of biomolecules with modifications. [ABSTRACT FROM AUTHOR]

Stir-bar sorptive extraction (SBSE) is a popular solvent-less sample preparation method, which is widely applied for the sampling and preconcentration of a wide range of non-polar solutes. A typical stir-bar for SBSE is composed of a polydimethylsiloxane (PDMS) film, coated onto a glass jacket with an incorporated magnet core. Sampling is carried out by direct immersion or by exposing the stir-bar to the headspace of the sample. To-date the majority of reported SBSE devices have used PDMS as the sorbent, with a few alternative commercially SBSE coatings available (such as polyethylene glycol and polyacrylate), which limits the applicability of SBSE to more polar and hydrophilic solutes. The interest in more selective extraction has been the driving force behind the recent development of novel SBSE coatings, particularly those exhibiting selectivity towards more polar solutes. During the last decade, a significant number of novel SBSE coatings were introduced utilising different fabrication approaches, including surface adhesion, molecular imprinting, sol-gel technology, immobilised monoliths, and solvent exchange processes. A range of nano- and micro-carbon-based materials, functional polymers, metal organic frameworks (MOFs), and inorganic nanoparticles have been employed for this purpose. Some of these SBSE coatings have exhibited higher thermal and chemical stability and delivered wider selectivity profiles. This review aims to summarise these significant developments, reported over the past six years, with specific attention to novel materials and selectivity for extending the potential applications of SBSE. Image 1 • Critical evaluation of advances in SBSE coatings over the past six years. • Discussion of latest techniques for production of SBSE coatings. • Evaluation of stabilities, selectivity, and applications of novel SBSE coatings. [ABSTRACT FROM AUTHOR]

Although antibody has played a great role in highly specific recognition of protein biomarkers, it faces poor stability, reproducibility, high-cost and time-consuming preparation, etc. Here, aptamer and molecularly imprinted polymers (MIPs), both as promising substitutes of antibody, were integrated onto magnetic nanoparticles by Au–S bonds and SiO 2 as imprinted layer for preparing a new nanoprobe. Highly specific and sensitive recognition of different protein biomarkers, such as insulin for diabetes and alpha-fetoprotein (AFP) for hepatic carcinoma, were achieved respectively by the system of combining hybrid aptamer-molecularly imprinted magnetic nanoprobe and mass spectrometry. With the double affinities offered by aptamer-MIPs, insulin can be detected at 0.5 ng mL−1 in human serum dilution, the equlibrium dissociation constant between nanoprobe and insulin is measured as 23.61 ± 2.27 μM. Likewise, AFP can be sufficiently detected in human saliva dilution from 1000 ng mL−1 to 20 ng mL−1, and two patients with hepatic carcinoma are discriminated from healthy person due to the abnormally high expression of AFP in serum. Mag Au@SH-aptamer@MIP nanoprobe was fabricated and employed in detection of insulin or alpha-fetoprotein from human serum by MALDI-TOF MS. Image 1 • Nanoprobe with aptamer and molecularly imprint polymer dual-recognition is designed for protein biomarker detection. • TThe mass spectrometry detection limit of insulin in serum is as low as 0.5 ng mL−1. • Disease individuals can be identified through abnormally high levels of alpha-fetoprotein. [ABSTRACT FROM AUTHOR]

The use of dual recognition and multiple detection modes is an attractive strategy for realising sensors with improved selectivity and accuracy. Herein, a molecularly imprinted polymer (MIP)-based sensor is developed for amoxicillin detection based on two detection modes (fluorescence and electrochemiluminescence) and dual recognition. First, graphene oxide loaded with CdTe quantum dots/gold nanoparticles (GO/CdTe/Au NPs) is coated onto an indium tin oxide (ITO) electrode. Then, 4-mercapto-calix[6]arene is bonded to GO/CdTe/Au NPs as the first recognition element, which then form a host–guest complex with the target molecule amoxicillin. Subsequently, as the second recognition element, an MIP is prepared on the ITO electrode. After amoxicillin is removed from the MIP, specific identification sites for amoxicillin are obtained. Furthermore, the GO/CdTe/Au NPs can generate fluorescence and electrochemiluminescence signals that are effectively quenched by amoxicillin. Therefore, on/off switching of these signals can be achieved through the elution or adsorption of amoxicillin. The dual detection modes are complementary and provide mutual authentication, which can improve the detection accuracy and application scope. Moreover, the dual recognition sites for amoxicillin, improve detection selectivity. The fluorescence and electrochemiluminescence modes have detection ranges of 5–1000 × 10−11 mol L−1 and 5–1500 × 10−11 mol L−1, respectively, with detection limits of 9.2 × 10−12 mol L−1 and 8.3 × 10−12 mol L−1, respectively. Image 1 • An amoxicillin sensor is fabricated based on two detection modes, with GO/CdTe/Au NPs used as an optical element. • Dual fluorescence and electrochemiluminescence detection modes improve accuracy. • Dual recognition sites (4-mercapto-calix[6]arene /molecularly imprinted polymer) impart selectivity. [ABSTRACT FROM AUTHOR]

Recent studies have shown anomalies with the most studied non-covalent molecularly imprinted polymer, the propranolol imprinted one. This imprinted polymer, like many others, binds more template than the non-imprinted control polymer, but its selectivity in template adsorption is only slightly or not at all improved by imprinting, depending on the compound compared. The reasons for this anomaly are discovered here. Simple experiments show that acid homoassociation in the prepolymerisation complex is the likely cause of the anomaly. The specific conductivity of prepolymerization mixtures at different functional monomer to template ratios follows a pattern observed in homoassociating systems. Analysis of the optimal prepolymerization mixture shows that on average two molecules of the functional monomer are complexed to the basic template, even if the template lacks any other hydrogen bonding functional group than the amino group. Molecular modeling calculations provide the structure and stability of the homoassociated prepolymerization complexes. These results lead to a plausible interpretation of the anomaly, which may not be unique for the propranolol imprinted polymer, but may affect all imprinted polymers made for basic templates by using acidic functional monomers. The analytical applications of the new imprinting model are demonstrated. Image 1 • Imprinting with amines is shown to induce homoassociation of acidic monomer. • Homoassociated acid binding site is stronger acid than single acid site. • Homoassociation increases the template rebinding and the class selectivity. • Selectivity towards related compounds is modestly changed by imprinting. • Consequences for analytical method development are demonstrated. [ABSTRACT FROM AUTHOR]

Molecularly imprinting polymers (MIPs), as artificial antibodies with high recognition selectivity to template molecules, are widely used in various biosensors. To improve further the selectivity of MIPs-based photoelectrochemical (PEC) biosensors, we report a differential strategy using non-imprinted polymers (NIPs) as the reference. In a proof-to-concept example for the determination of dopamine (DA), MIPs and NIPs membranes were fabricated by electrochemical polymerization of polypyrrole membranes on the surface of graphene quantum dots (GQDs)/TiO 2 nanotubes (NTs). The photocurrent difference between the two PEC cells, MIPs@GQDs/TiO 2 NTs−Pt and NIPs@GQDs/TiO 2 NTs−Pt, was measured as the signal. As the non-specific adsorption of non-template molecules on the outside surface of MIPs and NIPs membranes is similar, the anti-interference ability for the determination of DA is much improved by using differential strategy. In the normal and differential PEC measurement models, 10.0 μM ascorbic acid is equivalent to 3.12 and 0.40 μM DA, respectively. Further, the smaller specific surface area in NIPs membrane was compensated by using a weight factor to correct the residual interference in a modified differential model. By using 10.0 μM ascorbic acid as the balance point, the presence of 10.0 μM H 2 O 2 , glutathione, uric acid or glucose is equivalent only to 0.090, 0.061,0.11 or 0.041 μM of DA, respectively, which are about 3–7% of their interference levels in the normal photocurrent model. The differential PEC method was applied in the determination of DA in serum samples in the linear range of 0.05–12.5 μM, with the detection limit of 0.018 μM. Image 1 • The selectivity of molecularly imprinted polymers (MIPs) sensor is improved via differential strategy. • Non-imprinted polymers (NIPs) are used as reference to correct the influence of non-specific adsorption. • A modified differential method is reported with enhancing anti-interference ability. • The interference in differential photocurrent signal is about 3–7% of that in normal one. [ABSTRACT FROM AUTHOR]

A molecularly imprinted polymer (MIP) has been prepared in presence of 3-hydroxy phencyclidine (3-OH PCP) as template by bulk polymerization using N,N -dimethylformamide, as porogenic solvent, for the selective solid-phase extraction (SPE) of arylcyclohexylamines from oral fluids. Experimental variables of the extraction procedure have been studied in order to increase both, extraction recovery of 3-OH PCP, used as model analyte, and imprinting factor. By modifying the composition of the washing solvent, the selectivity of the MIP extraction procedure can be tuned, moving from an arylcyclohexylamine selective method to a 3-OH PCP specific method. The applicability of the synthesized MIP was evaluated by the analysis of oral fluids spiked with 3-OH PCP at different concentration levels, extracted using both recommended SPE procedures and analyzed by ion mobility spectrometry. Recovery values ranging from 70 to 101% and a limit of detection of 15 μg L−1 were obtained. Image 1 • Molecularly imprinted polymer using 3-OH PCP as template was synthetized. • Molecular modelling was used to predict analyte:monomer binding energies. • Selective solid-phase extraction of arylcyclohexylamines from oral fluids. • Tuning the selectivity of the MIP extraction by modification of washing step. • From class selective to specific extraction method. [ABSTRACT FROM AUTHOR]

Calcium fluoride (CaF 2) quantum dots have many applications in various fields. But there is no report on fluorescent characteristics of CaF 2 quantum dots (CaF 2 QDs). Here, a synthesis of multiple-color emission CaF 2 QDs by changing the temperature, time and raw ratio is reported, by which the CaF 2 QDs with purple, blue, green, and yellow emission can be obtained, respectively. They were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). On this basis, a novel molecular imprinting ratiometric fluorescence sensor (MIR sensor) had been constructed based on the prepared CaF 2 QDs and CdTe QDs, in which the yellow emission CaF 2 QDs was used as a responsive signal material and the red emission CdTe QDs was served as a reference signal material. And the β-CD and methylacrylic acid (MAA) as bifunctional monomers were used for constructing the specific molecularly imprinted polymers (MIPs) in MIR sensor. This MIR sensor was applied for highly selective and excellent sensitive detection of 5-hydroxymethylfurfural (HMF). Under optimum conditions, it exhibited an excellent linear relationship between the fluorescence intensity ratio (I 599 /I 625) and the concentration of HMF in the range of 0.1–6.0 μg/mL with a detection limit of 0.043 μg/mL. Finally, the established HMF-MIR sensor was successfully utilized to detect HMF in honey with satisfactory results. This work provided a reference for the application of the CaF 2 QDs and the detection of the furfural substances. Image 1 • The multiple color emission CaF 2 QDs had been synthesized for the first time. • A novel MIR sensor based on CaF 2 QDs was used for the visual detection of HMF in honey. • A specific HMF-MIR sensor had been constructed by using β-CD and MAA as functional monomers. [ABSTRACT FROM AUTHOR]

The preparation and practical applications of molecularly imprinted electrochemical sensors (MIECSs) remain challenging due to issues involving electrode surface renewal modes, low adsorption capacities, and sample preparation speeds. To solve these issues, magnetic molecularly imprinted electrochemical sensors (MMIECSs) have been extensively explored by various groups. Recently, MMIECSs fabricated based on diverse strategies have yielded insight into the development of MIECSs, and they have provided effective paths for sample preparation, immobilization and renewal of molecularly imprinted polymers (MIPs) on the electrode surface, leading to promising performances of MIECSs. This review comprehensively describes the research advances for various types of MMIECSs and their applications in the fields of food safety, environmental monitoring, and clinical and pharmaceutical analysis. Based on our understanding of MMIECSs, the literature in this field is thoroughly explored and classified in this review. The challenges existing in this research area and some potential strategies for the rational design of high-performance MMIECS are also outlined. Image 1 • Magnetic molecularly imprinted electrochemical sensors (MMIECSs) are commented. • MMIECS is a promising mode derived from MIPs-based electrochemical sensors. • MMIECS applications in the analytical field are extensively reviewed. • Future perspectives and challenges of MMIECS are discussed briefly. [ABSTRACT FROM AUTHOR]

Possibilities of room temperature spectrometry based on Mn-doped ZnS quantum dots coated with a molecularly imprinted polymer based nanosensor have been explored for the sensitive and selective determination of aflatoxins. Synthesized polymeric nanoparticles exhibit intense room temperature phosphorescence (total decay time of 0.004 s) and aflatoxins quench the room temperature phosphorescence when interact with the recognition cavities of the molecularly imprinted polymer attached to the phosphorescent quantum dots. Room temperature phosphorescence was recorded by scanning from 520 nm to 720 nm (maximum peak intensity at 594 nm) after excitation at 290 nm. The prepared imprinted material was found to have higher adsorption capacity than those based non-imprinted quantum dots, demonstrating high adsorption uptake for aflatoxins. In addition, selectivity studies have demonstrated that the material offers a specific recognition for aflatoxins. Room temperature phosphorescence quenching by aflatoxins was found to be linear within the 2–20 μg L−1 range, and a limit of detection of 3.56 μg kg−1 was obtained. This value was lower than the maximum acceptable/residual level (aflatoxins in feeds) published by the European Commission. The results indicate a simple room temperature phosphorescence nanosensor for aflatoxins detection in fish feed as a versatile tool having excellent sensitivity and selectivity. Image 1 • Room temperature phosphorescence nanosensor offers high sensitivity for aflatoxins determination. • High selectivity for aflatoxins inherent to the molecularly imprinted polymer layer attached to the quantum dot. • Determinations based on room temperature phosphorescence are free of matrix effect. • Simple and low cost assessment of aflatoxins in complex materials. [ABSTRACT FROM AUTHOR]

In this paper, molecular imprinting and photonic crystal techniques were combined to construct a four-channel sensor array for the simultaneous identification of various sulfonamides. The assay was composed of four units. Three of these units were prepared using sulfaguanidine, sulfamethazine, or sulfathiazole as template molecules. The fourth unit was prepared without a template molecule. The preparation was optimized to obtain maximum identification with a molar ratio of template, monomer, and cross-linker of 1:50:10. The response time was as short as 10 min. For demonstration, six sulfonamides were selected as analytes. The Bragg diffraction patterns of analytes at different concentrations were measured using the sensor array. Data obtained were analyzed using linear discrimination analysis (LDA) and principal component analysis (PCA). LDA can be applied for SAs discrimination. The message ratios of 87.6%, 94.4%, and 95.8% for six SAs at 10−4 mol L−1, 10−6 mol L−1, and 10−8 mol L−1 were achieved using LDA. The sensor array identified the mixture containing various SAs with an LDA coefficient of 86.1%, thereby indicating that the sensor array had a strong anti-interference ability. The sensor array was used to identify six SAs in fish samples. The measured data in spiked samples were consistent with the fingerprint collected from standard solutions. The accuracy rate reached 90.9%, indicating that the array can be used to identify SAs from food samples. Image 1 • Photonic crystal imprinting array was firstly reported for sulfonamide discrimination. • The applicable concentration range of sulfonamide is wide (10−4–10−8 mol/L). • The response is rapid and label-free. • The array was applicable in food analysis. [ABSTRACT FROM AUTHOR]

We designed a new type of MIP-SERS substrate for specific and label-free detection of patulin (PAT), by combining molecular imprinting polymer (MIP) selectivity and SERS technology sensitivity. Initially, the solid substrate of PDMS/AAO was prepared using poly dimethylsiloxane (PDMS) concreted anodized aluminum oxide (AAO) template. Then moderate Au was sputtered on the surface of PDMS/AAO to obtain Au/PDMS/AAO SERS substrate. Based on the HRP enzyme initiated in situ polymerization on the Au/PDMS/AAO, the MIP-SERS substrate was successfully synthesized with selective polymer and high tense of SERS "hot spots". The new MIP-SERS substrate showed strong SERS enhancement effect and good selectivity for PAT. Besides, the results showed that the method owned a linear range from 5 × 10−10 to 10−6 M with the limit of detection (LOD) of 8.5 × 10−11 M (S/N = 3) for PAT. The proposed method also exhibited acceptable reproducibility (relative standard deviation, RSD = 4.7%)，good stability (Raman intensity is above 80% after two weeks) and recoveries from 96.43% to 112.83% with the average RSD of 6.3%. The substrate is easy to use without complex sample pretreatment, which makes it a potential candidate as a rapid and sensitive detection method in food samples. Image 1 • A new type of MIP-SERS substrate which combined the selectivity of molecular imprinting polymer (MIP) and the sensitivity of SERS technology was prepared with uniform structure and dense "hot spots". • The method behaved a wide linear range of 5×10 ‒10 to 10 ‒6 M with limit of detection of 8.5×10 ‒11 M. • The MIP-SERS substrate can be easily used without complex sample pretreatment. [ABSTRACT FROM AUTHOR]

We report the on-line coupling of a monolithic molecularly imprinted polymer to nano-liquid chromatography for the selective analysis of cocaine and its main metabolite, benzoylecgonine, in complex biological samples. After the screening of different synthesis conditions, a monolithic molecularly imprinted polymer was in situ synthesized into a 100 μm internal diameter fused-silica capillary using cocaine as template, methacrylic acid as functional monomer, and trimethylolpropane trimethacrylate as cross-linker. Scanning electron microscopy was used to assess the homogeneous morphology of the molecularly imprinted polymer and its permeability was measured. Its selectivity was evaluated by nano-liquid chromatography-ultraviolet, leading to imprinting factors of 3.2 ± 0.5 and 2.2 ± 0.3 for cocaine and benzoylecgonine, respectively, on polymers resulting from three independent syntheses, showing the high selectivity and the repeatability of the synthesis. After optimizing the extraction protocol to promote selectivity, the monolithic molecularly imprinted polymer was successfully on-line coupled with nano-liquid chromatography-ultraviolet for the direct extraction and analysis of cocaine present in spiked human plasma and saliva samples. The repeatability of the obtained extraction recovery, between 85.4 and 98.7% for a plasma sample spiked at 100 ng mL−1, was high with relative standard deviation values lower than 5.8% for triplicate analyses on each of the three independently synthesized molecularly imprinted polymers. A linear calibration range was achieved between 100 and 2000 ng mL−1 (R2 = 0.999). Limits of quantification of 14.5 ng mL−1 and 6.1 ng mL−1 were achieved in plasma and urine samples, respectively. The very clean-baseline of the resulting chromatogram illustrated the high selectivity brought by the monolithic molecularly imprinted polymer that allows the removal of a huge peak corresponding to the elution of interfering compounds and the easy determination of the target analyte in these complex biological samples. Image 1 • In situ synthesis of monolithic cocaine molecularly imprinted polymers in capillary. • Characterizations of their permeability and selectivity optimization. • Evaluation of the synthesis repeatability for independent syntheses. • Optimization of the on-line monolithic MIP extraction and nanoLC separation. • Trace analysis of cocaine in spiked human plasma and saliva with 50 nL and in 20 min. [ABSTRACT FROM AUTHOR]

α-amanitin is the most toxic amanita in mushrooms with lethal dose to humans around 0.1 mg. Kg−1. Hence, early identification of the poison would improve survival rates and prevent lethal poisoning cases. In this study, molecularly imprinted photonic crystal (MIPC) sensor was prepared by combining molecular imprinting with photonic crystal templates and tested towards the detection of α-amanitin. In this process, synthesized moiety of α–amanitin was utilized as template, dispersed SiO 2 colloidal photonic crystal as carrier, methacrylic acid (MAA) as functional monomer, and ethylene glycol dimethacrylate (EDGMA) as crosslinker. The adsorption behavior of MIPC towards α-amanitin in ethanol solution showed shifts in diffraction peaks of MIPC upon binding with α-amanitin molecules. The reflection peak wavelength varied linearly with α-amanitin concentration according to the correlation formula: λ = 15.417 c +489.17 (R2 = 0.9985). The recognition process was accompanied by gradual color change in MIPC film. The prepared MIPC sensor possessed wide linear range (10−9–10−3 mg L−1), change in visual color, low detection limit (10−10 mg L−1), short response time (2 min), and good reusability. The MIPC film was then tested towards the detection of α-amanitin in real biological samples (mushroom, urine, and serum) and showed reasonable shift in diffraction peaks and color change upon soaking in solutions spiked with α-amanitin at 10−6 mg L−1 and 10−3 mg L−1, suggesting the suitability of the film for the rapid identification of α-amanitin in complex sample matrices. Overall, the proposed sensor looks promising for the rapid identification of α-amanitin in clinical analysis and food poisoning. Image 1 • The first report of recognition of α-amanitin by colorimetric sensor based on molecularly imprinted photonic crystal (MIPC). • The MIPC sensor possess change in visual color, low detection limit and short response time. • Adsorption capability and selectivity is fully adequate for rapid identification of α-amanitin in clinical analysis. [ABSTRACT FROM AUTHOR]

Herein, we describe the synthesis and characterisation of four synthetic recognition materials (nanoMIPs) selective for the glucocorticoid steroids – prednisolone, prednisone, dexamethasone, and cortisone. Using a solid-phase synthesis approach, these materials were then applied in the development of a surface plasmon resonance (SPR) sensor for the detection of these four targets in doped urine, to mimic the routine testing of agricultural waste for possible environmental exposure. The synthesised particles displayed a range of sizes between 104 and 160 nm. Affinity studies were performed, and these synthetic materials were shown to display nanomolar affinities (15.9–62.8 nM) towards their desired targets. Furthermore, we conducted cross-reactivity studies to assess the materials selectivity towards their desired target and the materials showed excellent selectivity when compared to the non-desired target, with selectivity factors calculated. Furthermore, through the use of 3D visualisation it can be seen that small changes between structures (such as a hydroxyl to ketone transformation) there is excellent selectivity between the compounds in the ranges of 100 fold plus. Using Surine™ doped samples the materials offered comparable nanomolar affinities (10.7–75.7 nM) towards their targets when compared to the standardised buffer preparation. Detection levels in urine for all compounds was in the nanomolar range. The developed sensor offers potential for these devices to be used in the prevention of these pharmaceutical compounds to enter the surrounding environment through agricultural waste through monitoring at source. Likewise, they can be used to monitor use in clinical samples. [Display omitted] • The generation of four novel synthetic recognition nanomaterials via molecular imprinting technology. • Affinity studies were performed, and materials displayed nanomolar affinities (15.9–62.8 nM) towards their target, with excellent selectivity. • Theoretical LODs in both PBS and Surine™ were calculated and materials displayed very low limits of detection as a SPR sensing device (1.3–6.5 nM). • These materials have the potential to replace chromatographic methods for the rapid detection of synthetic glucocorticoids in biological media. [ABSTRACT FROM AUTHOR]

The challenge of heavy biofouling in complex sweat environments limits the potential of electrochemical sweat sensors for noninvasive physiological assessment. In this study, a novel semi-interpenetrating hydrogel of PSBMA/PEDOT:PSS was engineered by interlacing PEDOT:PSS conductive polymer with zwitterionic PSBMA network. This versatile hydrogel served as the foundation for developing an anti-fouling wearable molecular imprinting sensor capable of sensitive and robust detection of tryptophan (Trp) in complex sweat. The incorporation of PEDOT:PSS conductive polymer into the semi-interpenetrating hydrogel introduced diverse physical crosslinks, including hydrogen bonding, electrostatic interactions, and chain entanglement. This incorporation considerably boosted the hydrogel's mechanical robustness and imparted commendable self-healing property. At the same time, the synergistic coupling between the well-balanced charge of the zwitterionic network and the high conductivity of the PEDOT:PSS polymer facilitated efficient charge transfer. The formation of the desired molecular imprinting membrane of semi-interpenetrating hydrogel was triggered by self-polymerization of dopamine (DA) in the presence of Trp. The designed biosensor demonstrated good sensitivity, selectivity and stability in detecting the target Trp. Notably, it also exhibited exceptional anti-fouling abilities, allowing for accurate Trp detection in complex real sweat samples, yielding results comparable to commercial enzyme-linked immunoassay (ELISA). A novel semi-interpenetrating PSBMA/PEDOT:PSS hydrogel was engineered to develop an anti-fouling wearable molecular imprinting sensor for robust detection of tryptophan in sweat. [Display omitted] • A novel and versatile semi-interpenetrating hydrogel of PSBMA/PEDOT:PSS was engineered. • The hydrogel exhibited good mechanical strength, self-healing, and anti-fouling properties. • A wearable molecular imprinting electrochemical sensor based on the hydrogel was developed. • The anti-fouling sensor enabled sensitive and robust detection of tryptophan in sweat. [ABSTRACT FROM AUTHOR]

Modern bioanalysis, which involves the quantitative and qualitative determination of small-molecule endogenous and exogenous substances in biological samples, is a powerful and useful tool that can generate valuable information related to many areas connected with human health and quality of life. Although LC-MS and GC-MS are widely viewed as the gold standards for many bioanalytical tasks, the scientific community has not abandoned its search for newer, more efficient, and more inexpensive methods of performing extraction as a sample preparation step before final analysis. Recent research showing the immense potential of 3D printing compelled our group to explore how this technology could be applied to techniques used in analytical chemistry. In particular, 3D printing offers three promising advantages: availability, low cost of materials and equipment, and the ability to fabricate objects of nearly any shape to suit the needs of a given application. Previously, we demonstrated that a commercial 3D material (LAY-FOMM) can function as a chemically active object that enables the reversible sorption of the antidiabetic drug, glimepiride, and endogenous steroids. In this report, we use a 3D printer to fabricate sorbents with a scabbard-like shape for use with a 96-blade system, which, along with the use of a 96-well plate, allows multiple extractions to be performed simultaneously. In order to assess the relative benefits of this 3D printed approach, we compare the performance of the proposed LAY-FOMM-based sorbent to that of the widely used C18 sorbent. Although the LAY-FOMM sorbent showed lower extraction recovery rates than the C18 sorbent, all of the other validation parameters suggest that it is suitable for use in high-throughput analysis of steroids in human plasma. Image 1 • Thermoplastic fabricated via 3D printing is capable of acting as a sorbent. • 3D printing enables to fabricate chemically active objects of desired shape. • 3D printing-based extraction protocol enabling high-throughput analysis. • The protocol can be applied in biomedical analyses. [ABSTRACT FROM AUTHOR]

In this work, we reported a novel electrochemical sensor for enantiorecognition of electrochemically inactive aspartic acid (Asp) enantiomers. By combining sol-gel processing with molecular imprinting technology, an enantioselective interface of molecularly imprinted sol-gel (MIS) films with imprinted cavities was prepared on the surface of a glassy carbon electrode (GCE). In order to obtain the electrochemical responses of electrochemically inactive Asp, the ternary derivative of L -aspartic, (l -aspartic acid)Cu2+(N -carbobenzoxy- l -aspartic acid), was used as the template for fabrication of MIS. The stripping currents of target molecules could be detected by square-wave stripping voltammetry due to the reduction of cupric ion on the modified electrode. The resulted sensor showed good adsorbability to L -Asp derivative, and the recognition efficiency was obtained as 2.1. Meanwhile, the L -Asp was quantitatively determined by the MIS sensor. As a result, the proposed electrochemical sensor could be regarded as a potential platform for enantiorecognition of electrochemically inactive chiral compounds. Image 1 • By combining sol-gel processing with molecular imprinting, an enantioselective interface of MIS films was constructed. • The derivative chiral copper complexes were used as template to obtain the response of electrochemical-inactive Asp. • The recognition efficiency was evaluated as 2.10. [ABSTRACT FROM AUTHOR]

As a typical antibiotic that is harmful to the health of human beings and widely used in animal husbandry, oxytetracycline (OTC) has a potential threat to the food safety. Therefore, the design of portable sensors for efficiently monitoring trace amounts of OTC in foods is vital to maintain safe food supply in our daily life. Herein, a two-dimensional (2D) molecularly imprinted photonic crystal hydrogel (MIPCH) sensor for the detection of OTC was fabricated by combining the photonic crystal (PC) method and molecular imprinting technique. In this regard, OTC was used as imprinted template to form the MIPCH sensor with specific binding sites during polymerization. After the removal of template, the obtained MIPCH possessed the specific nanocavities that were complementary to target compound, OTC. In addition, the response of the MIPCH to tetracyclines (TCs) in aqueous solution was monitored through a readable change of Debye diffraction ring, which is related to the particle spacing variation of MIPCH in response to the target molecules. As the concentration of OTC increased from 0 to 60 μM, the particle spacing of MIPCH sensor increased to about 94 nm and the structural color redshifted from blue to red. More importantly, the detection of OTC in milk sample by this portable, cost-effective MIPCH sensor has also been achieved at the same range of OTC. With the increasing concentration of OTC in milk sample, the particle spacing of MIPCH sensor increased about 92 nm and the structural color of MIPCH changed from blue through green to orange. Image 1 • A novel 2D molecularly imprinted PC was developed for the fast screening of trace level residues of OTC in milk. • The detection could be realized by naked eyes through observing the diffraction ring or structural color. • The sensor also showed advantages in easy preparation and specificity towards the targets. [ABSTRACT FROM AUTHOR]

In this study, a novel and green synthesis of a new hydrophilic molecularly imprinted 3-aminophenol−hexamethylenetetramine (MIAPH) resin for the selective recognition and separation of plant hormones was developed. The MIAPH resin was obtained using 3-aminophenol as multifunctional monomer which introduced hydroxyl, amino, and imino groups simultaneously, and adenine was used as a dummy template for molecular imprinting. Meanwhile, hexamethylenetetramine released formaldehyde slowly through hydrolysis which was used as the cross-linking agent to avoid the direct and excessive use of toxic formaldehyde. The entire procedure was performed under mild conditions, and was facile, environmentally friendly and energy-efficient. The obtained MIAPH resin showed high specific recognition toward plant hormones and higher recoveries in bean sprouts compared to NIAPH, HLB, and C 18. Various parameters affecting the extraction efficiency were optimized, and the calibration linearity of the MIAPH‒SPE‒HPLC method was determined from 0.07 to 2.86 mg kg−1 with a correlation coefficient (r) ≥ 0.9994 under the optimal conditions. Recoveries of spiked standards ranged from 90.2 to 99.1% for bean sprout with a relative standard deviation of ≤5.3%. Finally, the established MIAPH‒SPE‒HPLC method was successfully applied for the selective extraction and sensitive detection of plant hormones in a variety of complex vegetable matrices. Image 1 • A new hydrophilic molecularly imprinted resin was prepared via green protocol. • The material exhibited excellent recognition towards plant hormones. • The material owned higher extraction efficiency than commercial adsorbents. • A new method was developed for detection of plant hormones in bean sprouts. [ABSTRACT FROM AUTHOR]

Abstract In this study, a molecularly imprinted polymer photoelectrochemcal (MIP-PEC) sensor based on semiconducting organic polymer dots (Pdots) and inorganic CdS quantum dots (QDs) has been established for the determination of α-Solanine. Specifically, p-type Pdots (p-Pdots) and n-type CdS QDs (n-CdS) were utilized to form organic-inorganic nanoparticles p-n heterojunction to enhance signal response, and their specific energy levels (VB/CB or HOMO/LUMO) were calculated for photoelectrochemical (PEC) bioanalysis application. At the same time, the combination of molecular imprinting technology and photoelectrochemistry overcomes the defeats of photoelectrochemistry which is the absence of selectivity, offers a new MIP-PEC sensor with high sensitivity and excellent selectivity based heterojunction enhanced strategy. In short, this study proposes the semiconducting organic-inorganic nanoparticles p-n heterojunction for molecularly imprinted polymer photoelectrochemcal bioanalysis application, and the MIP-PEC sensor was successfully fabricated based on these materials and methods. In the phosphate buffer solution (PBS), it was clearly observed that the photocurrent has a significant change between elution in acetic acid-ethanol mixture and incubation in template molecular solution because of the faster electron transfer speed, this phenomenon fully showed that the MIP-PEC sensor can specifically detect the target. Thus, the work typically offers a linear range from 0.01 to 1000 ng mL−1 with a detection limit of 6.5 pg mL−1 for α-Solanine. Furthermore, the fabricated MIP-PEC sensor will confirm the actual application. Graphical abstract Image 1 Highlights • Organic polymer dots (Pdots) and CdS quantum dots were utilized to construct the organic-inorganic nanoparticles heterojunction. • A p-n heterojunction as photoelectric conversion layer to prepare MIP-PEC sensor equipped with their specific energy levels. • The preparing of molecularly imprinted photoelectrochemical sensor for α-Solanine determination had not been reported so far. • The method can be extended to real sample detection and provides ideas for detection of other substances in future work. [ABSTRACT FROM AUTHOR]

Abstract In this work, molecularly imprinted polymers (MIPs) were prepared with vinyl-coated magnetic particles (Fe 3 O 4 @VTEO) as the support material, deep eutectic solvent (DES) based on vinyl as the functional monomer, respectively. N,N-methylenebisacrylamide (MBAAm) was used as the crosslinker on account of its abundant carbon-carbon double bonds. The MIPs were prepared with the addition of bovine hemoglobin (BHb) acted as the template. The MIPs particles can be collected quickly by a magnetic field. The composition and morphology of the MIPs particles were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), fourier transform infrared spectrometry (FT-IR) and thermo-gravimetric analysis (TGA). X-ray diffraction (XRD) was used to illustrate the cubic inverse spinel structure of Fe 3 O 4. Meanwhile, vibrating sample magnetometer (VSM) was applied to characterize the magnetism of the MIPs. Adsorption experiments were performed to attain the optimum adsorption conditions. Under the optimized conditions, the obtained maximum adsorption capacity (Q, mg·g−1) of the MIPs particles is found to be 164.20 mg g−1, and the imprinting factor (IF) is 4.93. Four reference molecules were used to test the selectivity of the MIPs particles, which indicates that the recognition sites can adsorb template molecules with selectivity. Furthermore, the prepared magnetic MIPs particles were applied to capture BHb from the real samples (calf blood) effectively. Graphical abstract Image 1 Highlights • New magnetic molecularly imprinted polymers (DES-Fe 3 O 4 @MIPs) were prepared based on deep eutectic solvent (DES). • DES is a kind of eco-friendly solvent. • Adsorption experiments were explored to attain the optimum adsorption conditions. • The MIPs particles were applied to capture BHb from the real calf blood samples effectively. [ABSTRACT FROM AUTHOR]

Abstract In this work, a novel molecularly imprinted stir-bar was developed for the stir-bar sorptive extraction (SBSE) of thiabendazole (TBZ) and carbendazim (CBZ) from orange samples. Magnetic nanoparticles were surface modified with oleic acid and then encapsulated by a silica shell using a conventional sol-gel procedure. Subsequently, nanoparticles were functionalized with methacrylate functionalities by grafting onto the particles surface. Finally, the modified magnetic nanoparticles were entrapped in a polymer monolith synthetized by copolymerization with the imprinting polymerization mixture using a glass vial insert as a mold. Variables affecting the polymerization and rebinding conditions of target analytes were optimized. The uptake capacity for the template (TBZ) was evaluated as well as the cross-reactivity for the related compound CBZ by rebinding experiments. Finally, the proposed magnetic imprinted monolith was applied to the SBSE of TBZ and CBZ from orange sample extracts providing a remarkable clean-up ability. The calculated detection limit were 0.13 and 0.10 mg kg−1 for CBZ and TBZ respectively, low enough to satisfactory analysis of both compounds in orange samples according to current European Union regulations. Graphical abstract Image 1 Highlights • A stir-bar based on an imprinted monolith polymer containing magnetic nanoparticles is developed. • MIP magnetic stir-bar for the stir-bar sorptive extraction of thiabendazole and carbendazim was studied. • Thiabendazole and carbendazim were successfully extracted from orange sample extracts. [ABSTRACT FROM AUTHOR]

Long-term and excessive exposure to bisphenol A (BPA) has an extremely detrimental effect on human health and ecological system. Hence, there is an urgent need to develop a sensitive and selective sensor for precisely monitoring BPA levels. In this work, a flexible and tailor-made electrochemical sensor for BPA has been fabricated based on in situ photopolymerization of molecular imprinting on cadmium sulfide (CdS) modified carbon felt (MIP@CdS-CF). It is worth nothing that CdS acts as a photocatalyst to enhance the capacity of photopolymerization, accordingly upgrading imprinting efficiency. Meanwhile, carbon felt (CF) exhibits attractive merits in term of superior electrical conductivity, enlarged electrochemical active areas and unique flexibility. Consequently, the novel MIP@CdS-CF electrochemical sensor shows superior sensitivity, high selectivity, extraordinary reproducibility and stability to detect BPA. The detection limit is 1.5 nM, which is lower than those of previously reported electrochemical sensors for the detection of BPA. More importantly, this newly developed electrochemical sensor can be utilized for detecting BPA in plastic bottles with satisfactory results. A flexible electrochemical biosensor based on photoinitiated molecular imprinting on CdS modified carbon felt for sensitive and selective detection of bisphenol A (BPA) in plastic bottles. [Display omitted] • Flexible electrode was constructed based on CdS functionalized carbon felts. • The recognition elements were in-situ formed on flexible electrode through photo-initiated molecular imprinting. • A sensitive and tailor-made electrochemical sensor for bisphenol A (BPA) was achieved. • CdS acts as a photocatalyst to enhance the capacity of photopolymerization, accordingly upgrading imprinting efficiency. [ABSTRACT FROM AUTHOR]

Sorafenib (SOR) is a multikinase inhibitor anticancer drug that is used in treating non-small cell lung cancer. In this work, we focused on developing nanomaterial-supported smart porous interfaces by following the molecular imprinting approach for the selective determination of SOR. Determination-based studies in the literature for SOR are limited, and they are chromatographic techniques-based; hence, there is a need in the literature to elaborate the selective and sensitive analysis/monitoring of SOR in both biological and pharmaceutical samples with more studies. The results showed that adding ZnO NPs enhanced the signal five times compared to the solo molecularly imprinted polymer (MIP). Under the optimized conditions, ZnO/AMPS@MIP-GCE showed a linear response in the concentration range between 1.0 × 10−12 and 1.0 × 10−11 M with LOD and LOQ values of 2.25 × 10−13 M and 7.51 × 10−13 M, respectively, in the serum sample. The selectivity study was conducted against common cations, anions, and compounds such as dopamine, paracetamol, ascorbic acid, and uric acid. Also, the imprinting factor (IF) analysis was performed on selected drug substances having structural similarities to SOR and the relative IF values of regorafenib, leflunomide, teriflunomide, nilotinib, axitinib, and dasatinib indicated the selectivity of the developed sensor for SOR. Finally, ZnO/AMPS@MIP-GCE was implemented to determine SOR in the spiked commercial human serum samples and tablet dosage form with bias% between −0.43 and + 0.66. This study is the first electrochemical study for the determination of SOR, and thanks to the ZnO NPs supported MIP sensor, it stands out in terms of both high sensitivity and superior selectivity. Also, this designed sensor provides controlled orientation of the template and complete removal of templates in a one-step process, allowing extremely low detection and quantification limits. [Display omitted] • First nanoparticle supported-MIP sensor for Sorafenib determination. • Accurate and effective analysis in biological and pharmaceutical samples. • High sensitivity and superior selectivity thanks to MIP. [ABSTRACT FROM AUTHOR]

Although electrochemical detection based on molecular imprinting polymers (MIP) could dramatically improve the selectivity, the procedure is time-consuming because of the essential incubation step. In addition, current MIP electrochemical detections were not suitable for analysis of microliter-level sample solutions, limiting their applications for real samples. This investigation aims at applying vibration to enhance efficiency of MIP electrochemical detection of 20 μL sample solutions. MIP analysis of Tryptophan (Trp) was used as the model with disposable MIP electrodes prepared by electrochemical polymerization of o-phenylenediamine on carbon ink coated on stainless steel sheets. The MIP electrode was integrated in a 3D-printed analytical device for vibration-enhanced electrochemical detection of Trp. Our results showed that this vibration-enhanced strategy could significantly increase electrochemical responses of Trp at the same incubation time. Such improvement might be attributed to the enhanced mass transfer at the surface of the working electrode brought by vibration. It needs to be emphasized that this strategy is suitable for analysis of sample solutions with the volume of microliters, which is superior to normal stirring in MIP electrochemical detection. Our approach could be successfully utilized for differentiation of Trp in different fruits, opening more opportunities for MIP electrochemical detection of real samples. The enhanced efficiency by vibration could pave foundation for extensive practical MIP detection of sample solutions at the level of microliters. [Display omitted] • Disposable MIP electrodes were prepared with stainless steel coated with carbon ink. • MIP electrodes were electrochemical polymerized with poly o-phenylenediamine and tryptophan. • Vibration could enhance analytical efficiency in the step of incubation in MIP detection. • This approach could be used for successful differentiation of tryptophan in fruits. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers, MIPs, are man-made receptors mimicking the thermodynamic and kinetic binding behaviour of natural antibodies. Therefore, it is not surprising that many researchers have thought about MIPs as artificial receptors in immunoassay-like analytical applications, where the general machinery of the assay is maintained, but the molecular recognition is no longer assured by an antibody but by an artificial receptor. However, the number of papers devoted explicitly to applications of MIPs in the immunoassay field is quite limited if compared to the huge number of papers covering the multifaceted molecular imprinting technology. For this reason, this critical review wants to give a general view of MIP-based immunoassays, trying to highlight the critical points that have so far prevented a wider application of molecular imprinting technology in the immunoassay field and, possibly, try to suggest strategies to overcome them. [Display omitted] • MIPs can mimic natural antibodies in immunoassay. • Innovative approaches have improved the binding properties of MIPs. • MIP-based immunoassays have passed by the proof-of-the-concept level to practical applications. • Several issues related to the development of robust assays still remain to be explored. [ABSTRACT FROM AUTHOR]

Whole-cell bacteria imprinted polymer-based sensors still face challenges in the form of the difficulty of removing the template entirely, low affinity, and poor sensitivity. To further improve their performance, it is pivotal to modulate the morphology and chemical properties of imprintied polymer by taking advantage of doping engineering. Here we introduced D-tartaric acid (D-TA) as a dopant and employed pyrrole as a functional monomer to construct D-TA/polypyrrole (PPy)-based bacteria imprinted polymer (DPBIP) sensor for Vibrio parahaemolyticus (VP) detection. It is demonstrated that D-TA doping can synergistically accelerate the removal of template bacteria from imprinted polymers (1.5 h), improve bacteria affinity of imprinted sites (the recognition time of 30 min), and enhance the sensitivity of DPBIP sensor (a detection limit of 19 CFU mL−1). The DPBIP sensor had a linear range of 102∼106 CFU mL−1 and exhibited high selectivity and good repeatability. Moreover, a recovery of 94.8%–105.3% was achieved in drinking water and oyster samples. Therefore, small functional molecules doping opens a new avenue to engineering BIP-based sensors with high performance, holding potential applications in securing food safety. [Display omitted] • D-TA/polypyrrole (PPy)-based bacteria imprinted polymer (DPBIP) sensor was constructed for Vibrio parahaemolyticus detection. • D-TA doping can synergistically accelerate template removal as well as increase the affinity and sensitivity of the DPBIP sensor. • The DPBIP sensor had a linear range of 102∼106 CFU mL−1with a detection limit of 19 CFU mL−1. • The DPBIP sensor exhibited high selectivity, good repeatability, and acceptable recovery. [ABSTRACT FROM AUTHOR]

Trace detection of argininosuccinate synthetase 1 (ASS1), a depression marker, in urine samples is difficult to achieve. In this work, a dual-epitope-peptides imprinted sensor for ASS1 detection in urine was constructed based on the high selectivity and sensitivity of the "epitope imprinting approach". First, two cysteine-modified epitope-peptides were immobilized onto gold nanoparticles (AuNPs) deposited on a flexible electrode (ITO-PET) by gold-sulfur bonds (Au-S), then a controlled electropolymerization of dopamine was carried out to imprint the epitope peptides. After removing epitope-peptides, the dual-epitope-peptides imprinted sensor (MIP/AuNPs/ITO-PET) which with multiple binding sites for ASS1 was obtained. Compared with single epitope-peptide, dual-epitope-peptides imprinted sensor had higher sensitivity, which presented a linear range from 0.15 to 6000 pg ml -1 with a low limit of detection (LOD = 0.106 pg mL -1 , S/N = 3). It had good reproducibility (RSD = 1.74%), repeatability (RSD = 3.60%), stability (RSD = 2.98%), and good selectivity, and the sensor had good recovery (92.4%-99.0%) in urine samples. This is the first highly sensitive and selective electrochemical assay for the depression marker ASS1 in urine, which is expected to provide help for the non-invasive and objective diagnosis of depression., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A novel molecularly imprinted ratiometric-based sensor was designed for highly selective and ultrasensitive electrochemical detection of glutathione (GSH). The sensor consists of porous carbon co-doped with nitrogen and sulfur formed on the surface of graphite electrode (N, S@PC/GE). Silver nanoparticles (Ag) were grown on the surface of N, S@PC/GE to improve the conductivity/surface area of the sensor and represent an internal reference signal for ratiometric response. The monomer (pyrrole-4-carboxylic acid, Py-COOH) was electro-polymerized on the surface of Ag/N, S@PC/GE in the presence of Cu (II) to form Cu-MIP@Ag/N, S@PC/GE. Addition of GSH decreased the signal of Ag at 0.18 V (oxidation of Ag) due to coordination complexation, while the signal response at 0.83 V (oxidation of Ag-GSH complex) was increased. Under optimum conditions, the ratio response (I GSH /I Ag ) was increased with increasing the concentration of GSH in the range of 0.01-500 nM with a detection limit (S/N = 3) of 0.003 nM. The electrochemical sensor exhibits many advantages including low LOD, high selectivity, good reproducibility, and satisfactory stability. The sensor was successfully applied to determine GSH in dietary supplements and human serum samples with recoveries % ranged from 97.4 to 101.8% and relative standard deviation % (RSD %) did not exceed 3.8%. This research paper introduces new information for the construction of molecular imprinted ratiometric-based electrochemical sensors for highly selective and sensitive detection of (bio) molecules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In this work, molecularly imprinted polymers (MIPs) were used on the surface of cadmium telluride quantum dots (CdTe QDs) for the simultaneous determination of folic acid (FA) and methotrexate (MTX). For this purpose, two different sizes of CdTe QDs with emission peaks in the yellow (QD Y ) and orange (QD O ) spectral regions were initially synthesized and capped with MIPs. FA and MTX were used as templates for the synthesis of the two composites and designated as QD Y -MIPs and QD O -MIPs, respectively. Fourier transform infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy were employed to characterize the composites. QD Y -MIPs and QD O -MIPs were then mixed (to form QDs-MIPs) and excited at identical excitation wavelengths; they emitted two different emission wavelengths without any spectral overlap. The fluorescence signals of QD Y -MIPs and QD O -MIPs diminished in intensity with increasing concentration of the corresponding template molecules. Under optimal conditions, the dynamic range was 0.5–20 μmol L −1 for FA and MTX, and the detection limits for FA and MTX were 32.0 nmol L −1 and 34.0 nmol L −1 , respectively. The reproducibility of the method was checked for 12.5 μmol L −1 of FA and MTX to find RSD values of 4.2% and 6.3%, respectively. Finally, the applicability of the method was checked using human blood plasma samples. Results indicated the successful application of the method as a fluorescent probe for the rapid and simultaneous detection of FA and MTX in real samples. [ABSTRACT FROM AUTHOR]

Determination of specific target compounds in agriculture food and natural plant products is essential for many purposes; however, it is often challenging due to the complexity of the sample matrices. Herein we present a new approach called plasmonic affinity sandwich assay for the facile and rapid probing of glucose and fructose in plant tissues. The approach mainly relies on molecularly imprinted plasmonic extraction microprobes, which were prepared on gold-coated acupuncture needles via boronate affinity controllable oriented surface imprinting with the target monosaccharide as the template molecules. An extraction microprobe was inserted into plant tissues under investigation, which allowed for the specific extraction of glucose or fructose from the tissues. The glucose or fructose molecules extracted on the microprobe were labeled with boronic acid-functionalized Raman-active silver nanoparticles, and thus affinity sandwich complexes were formed on the microprobes. After excess Raman nanotags were washed away, the microprobe was subjected to Raman detection. Upon being irradiated with a laser beam, surface plasmon on the gold-coated microprobes was generated, which further produced plasmon-enhanced Raman scattering of the silver-based nanotags and thereby provided sensitive detection. Apple fruits, which contain abundant glucose and fructose, were used as a model of plant tissues. The approach exhibited high specificity, good sensitivity (limit of detection, 1 μg mL −1 ), and fast speed (the whole procedure required only 20 min). The spatial distribution profiles of glucose and fructose within an apple were investigated by the developed approach. [ABSTRACT FROM AUTHOR]

Owing to their intrinsic amplifying effect together with chemical stability, graphene electrochemical transistor sensors (GECTs) are gaining momentum for sensing applications. However, the surface of GECTs for different detection substances must be modified with different recognition molecules, which was cumbersome and lack a universal method. Molecularly imprinted polymer (MIP) is a kind of polymer with specific recognition function for given molecules. Here, MIP and GECTs were combined to effectively solve the problem of weak selectivity of GECTs, and achieve the high sensitivity and selectivity of MIP-GECTs equipment in detecting acetaminophen (AP) in complex urine environment. A novel molecular imprinting sensor based on Au nanoparticles modified zirconia (ZrO 2) inorganic molecular imprinting membrane on reduced graphene oxide (ZrO 2 -MIP-Au/rGO) was proposed. ZrO 2 -MIP-Au/rGO was synthesized by one-step electropolymerization using AP as template, ZrO 2 precursor as the functional monomer. The –OH group on ZrO 2 and the –OH/–CONH– group on AP were easily bonded by hydrogen bonding to form a MIP layer on the surface, which allows the sensor to have a large number of imprinted cavities for AP specific adsorption. As a proof of method, the GECTs based on ZrO 2 -MIP-Au/rGO functional gate electrode has the characteristics of wide linear range (0.1 nM-4 mM), low detection limit (0.1 nM) and high selectivity for AP detection. These achievements highlight the introduction of specific and selective MIP to GECTs with unique amplification function, which could effectively solve the problem of selectivity of GECTs in complex environments, suggesting the potential of MIP-GECTs in real-time diagnosis. [Display omitted] • Electropolymerization ZrO 2 was first proposed as an inorganic functional monomer. • ZrO 2 -MIP-Au/rGO was synthesized by one-step electropolymerization. • The combination of MIP and GECTs solves the problem of GECTs selectivity. • ZrO 2 -MIP-Au/rGO has abundant AP binding sites and excellent electrical conductivity. • MIP-GECTs paves the way for the detection of GECTs in complex environments. [ABSTRACT FROM AUTHOR]

The abuse of multiple antibiotics and anti-inflammatory drugs can harm the ecological environment and human health. Herein, a smartphone-integrated tri-color fluorescence sensing platform based on acid-sensitive fluorescence imprinted polymers was proposed for dual-mode visual intelligent detection of ibuprofen (IP), chloramphenicol (CAP), and florfenicol (FF). In this research, the dual-mode of tri-color ratiometric fluorescence imprinted sensor (TC-FMIPs) was realized at different pH environments for the detection IP, CAP, and FF. The fluorescence peak at 551 nm of TC-FMIPs was quenched in the presence of IP solution and fluorescence peak at 687 nm was quenched in the presence of CAP phosphate buffer solution (PBS, pH 7.0), while the fluorescence peak at 433 nm kept stable. Interestingly, the TC-FMIPs has a peroxidase-like activity, in which a new fluorescence peak at 561 nm was quenched and the fluorescence peak at 433 nm increased gradually with the addition of FF solution in pH 4.0 PBS. The TC-FMIPs showed a low detection limit of 10 pM, 8.5 pM, and 5.5 nM for IP, CAP, and FF, respectively. Additionally, a smartphone was used to capture of fluorescence colors and read out the RGB values for intelligent detection of IP, CAP, and FF, in which the detection limit was calculated as 15 pM, 12 pM and 7 nM toward IP, CAP and FF, respectively. The smartphone-integrated tri-color fluorescence sensing platform was developed for dual-mode visual intelligent detection of IP, CAP and FF successfully, which provided a new strategy for multi-target detection in the complex environment. [Display omitted] • A smartphone-integrated tri-color fluorescence sensing platform was proposed. • The dual-mode detection was realized handily under different pH conditions. • The smartphone-integrated sensing platform can detect intelligently IP, CAP, and FF. • A new fluorescence sensing platform for determination of multiple targets was developed. [ABSTRACT FROM AUTHOR]