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A novel and environmentally friendly molecularly imprinted polymer (PCA-MIP) was successfully synthesized in an aqueous solution for the selective extraction of protocatechuic acid (PCA). In this study, a deep eutectic solvent (DES, choline chloride/methacrylic acid, 1:2, mol/mol) and chitosan were employed as the eco-friendly functional monomers. These two components interacted with PCA through hydrogen bonding, integrating a multitude of recognition sites within the PCA-MIP. Thus, the resulting PCA-MIP exhibited outstanding adsorption performance, rapid adsorption rate, and better selectivity, with a maximum binding capacity of 30.56 mg/g and an equilibrium time of 30 min. The scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET) analyses revealed that the synthesized polymers possessed a uniform morphology and substantial surface areas, which were conducive to their adsorption properties. Moreover, the PCA-MIP integrated with HPLC demonstrated its efficacy as an adsorbent for the selective extraction of PCA from mango juice. The PCA-MIP presented itself as an exemplary adsorbent, offering a highly effective and eco-friendly method for the enrichment of PCA from complex matrices.

A new molecularly imprinted polymer (MIP)-based disposable electrochemical sensor for dipyridamole (DIP) determination was obtained. The sensor was rapidly prepared by potentiodynamic electrochemical polymerization on a pencil graphite electrode (PGE) using curcumin (CUR) as a functional monomer and DIP as a template molecule. After the optimization of the conditions (pH, monomer–template ratio, scan rate, number of cyclic voltammetric cycles applied in the electro-polymerization process and extraction time of the template molecule) for MIP formation, DIP voltammetric behavior at the modified electrode (MIP_PGE) was investigated. DIP oxidation took place in a pH-dependent, irreversible mixed diffusion-adsorption controlled process. Differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV) were used to quantify DIP from pharmaceutical and tap water samples. Under optimized conditions (Britton–Robinson buffer at pH = 3.29), the obtained linear ranges were 5.00 × 10−8–1.00 × 10−5 mol/L and 5.00 × 10−9–1.00 × 10−7 mol/L DIP for DPV and AdSDPV, respectively. The limits of detection of the methods were 1.47 × 10−8 mol/L for DPV and 3.96 × 10−9 mol/L DIP for AdSDPV.

Teicoplanin has been banned in the veterinary field due to the drug resistance of antibiotics. However, teicoplanin residue from the antibiotic abuse of humans and animals poses a threat to people’s health. Therefore, it is necessary to develop an efficient way for the highly accurate and reliable detection of teicoplanin from humans, food, and water. In this study, novel imprinted quantum dots of teicoplanin were prepared based on boronate affinity-based precisely controlled surface imprinting. The imprinting factor (IF) for teicoplanin was evaluated and reached a high value of 6.51. The results showed excellent sensitivity and selectivity towards teicoplanin. The relative fluorescence intensity was inversely proportional to the concentration of teicoplanin, in the range of 1.0–17 μM. And its limit of detection (LOD) was obtained as 0.714 μM. The fluorescence quenching process was mainly controlled by a static quenching mechanism via the non-radiative electron-transfer process between QDs and the five-membered cyclic boronate esters. The recoveries for the spiked urine, milk, and water samples ranged from 95.33 to 104.17%, 91.83 to 97.33, and 94.22 to 106.67%, respectively.

This study focuses on the synthesis, fabrication, and characterization of a molecularly imprinted polymer (MIP) sensor tailored for the selective determination of 4,4′-oxydianiline (4,4′-ODA) in plastic products. Notably, by integrating the sensor matrix with pyrolyzed copper/carbon material derived from Cu-BTC MOF, a remarkable enhancement in electrochemical performance is achieved. The Cu-BTC material is grown successfully on the surface of carbon nanotubes (CNTs) and subjected to calcination at 800 °C, yielding a CNT/Cu/C composite. This composite exhibits an increased surface area and enhanced electron transfer capability, resulting in an improved current response. To augment the selective detection capability of the modified electrodes for 4,4′-ODA, molecularly imprinted polymers (MIPs) were incorporated onto the composite surface. The modified electrode (CNT-2/Cu/C/MIP/GCE) was synthesized using acrylamide (AM) and methacrylic acid (MAA) as dual-functional monomers with 4,4′-ODA as a template molecule via precipitation polymerization. The differential pulse voltammetric (DPV) current response to 4,4′-ODA showed a favorable linear relationship within the concentration range of (0.15–10 μM,10–100 μM), with a detection limit of 0.05 μM. Moreover, the CNT-2/Cu/C/MIP/GCE sensor demonstrates exceptional sensitivity, specificity, consistency, and durability. Furthermore, this approach has proven effective in detecting 4,4′-ODA in spiked nylon spatula samples, with recovery rates ranging from 86.3% to 103.5%.

Acne vulgaris, a prevalent skin condition, arises from an imbalance in skin flora, fostering bacterial overgrowth. Addressing this issue, clindamycin molecularly imprinted polymeric nanoparticles (Clin-MIP) loaded onto polyurethane nanofiber scaffolds were developed for acne treatment. Clin-MIP was synthesized via precipitation polymerization using methacrylic acid (MAA), ethylene glycol dimethacrylate (EGDMA), and azoisobutyronitrile (AIBN) as functional monomers, crosslinkers, and free-radical initiators, respectively. MIP characterization utilized Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) before being incorporated into polyurethane nanofibers through electrospinning. Further analysis involved FTIR, scanning electron microscopy (SEM), in vitro release studies, and an ex vivo study. Clin-MIP showed strong antibacterial activity against S. aureus, with inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.39 and 6.25 μg/mL, respectively. It significantly dropped the bacterial count from 1 × 108 to 39 × 101 CFU/mL in vivo and has bactericidal activity within 180 min of incubation in vitro. The pharmacodynamic and histopathology studies revealed a significant decrease in infected animal skin inflammation, epidermal hypertrophy, and congestion upon treatment with Clin-MIP polyurethane nanofiber and reduced pro-inflammatory cytokines (NLRP3, TNF-α, IL-1β, and IL-6) conducive to acne healing. Consequently, the recently created Clin-MIP polyurethane nanofibrous scaffold. This innovative approach offers insight into creating materials with several uses for treating infectious wounds caused by acne.

In this study, a novel magnetic molecularly imprinted polymeric material (Fe3O4@MOF@MIP-160) with a metal-organic backbone (Fe3O4@MOF) carrier was prepared using dibutyl phthalate (DBP) as a template. The material can be used for the efficient, rapid, and selective extraction of trace amounts of phthalic acid esters (PAEs) in food and can detect them via gas chromatography-mass spectrometry (GC-MS). The synthesis conditions of the materials were optimized to prepare the Fe3O4@MOF@MIP160 with the highest adsorption performance. Transmission electron microscopy (TEM), Fourier Transform Infrared Spectra (FT-IR), Vibration Sample Magnetic (VSM), and the Brunauer–Emmett–Teller (BET) method were used to characterize the materials. Compared with Fe3O4@MOF and the magnetic non-imprinted polymeric material (Fe3O4@MOF@NIP), Fe3O4@MOF@MIP-160 possesses the advantages of easy and rapid manipulation of magnetic materials, the advantages of high specific surface area and the stability of metal–organic frameworks, and the advantages of high selectivity of molecularly imprinted polymers. Fe3O4@MOF@MIP-160 has good recognition and adsorption capacity for di-butyl phthalate (DBP) and diethylhexyl phthalate (DEHP): the adsorption capacity for DBP and DEHP is 260 mg·g−1 and 240.2 mg·g−1, and the adsorption rate is fast (reaching equilibrium in about 20 min). Additionally, Fe3O4@MOF@MIP160 could be recycled six times, making it cost-effective, easy to operate, and time-saving as compared to traditional solid-phase extraction materials. The phthalate ester content in drinking water, fruit juice, and white wine was analyzed, with recoveries ranging from 70.3% to 100.7%. This proved that Fe3O4@MOF@MIP160 was suitable for detecting and removing PAEs from food matrices.

This study addresses the necessity to monitor the presence of glyphosate (Gly) in waters, highlighting the need for on-site detection of Gly by using electrochemical sensors in environmental and agricultural monitoring programs. Two approaches were employed: (1) modification with graphene decorated with gold nanoparticles (AuNPs-Gr) and dispersed in either dimethylformamide (DMF) or a solution containing Nafion and isopropanol (NAF), and (2) molecularly imprinted polymers (MIPs) based on polypyrrole (PPy) deposited on gold SPEs (AuSPE). Electrochemical characterization revealed that sensors made of AuNPs-Gr/SPCE exhibited enhanced conductivity, larger active area, and improved charge transfer kinetics compared to unmodified SPEs and SPEs modified with graphene alone. However, the indirect detection mechanism of Gly via complex formation with metallic cations in AuNPs-Gr-based sensors introduces complexities and compromises sensitivity and selectivity. In contrast, MIPPy/AuSPE sensors demonstrated superior performance, offering enhanced reliability and sensitivity for Gly analysis. The MIPPy/AuSPE sensor allowed the detection of Gly concentrations as low as 5 ng/L, with excellent selectivity and reproducibility. Moreover, testing in real surface water samples from the Olt River in Romania showed recovery rates ranging from 90% to 99%, highlighting the effectiveness of the detection method. Future perspectives include expanding the investigation to monitor Gly decomposition in aquatic environments over time, providing insights into the decomposition’s long-term effects on water quality and ecosystem health, and modifying regulatory measures and agricultural practices for mitigating its impact. This research contributes to the development of robust and reliable electrochemical sensors for on-site monitoring of Glyphosate in environmental and agricultural settings.

An environmentally friendly and sustainable approach was adopted to produce a molecularly imprinted polymer (MIP) via electropolymerization, with remarkable electrochemical sensing properties, tested in tyrosine (tyr) detection. The 2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphtene (BT2-T4) was chosen as functional monomer and MIP electrosynthesis was carried out via cyclic voltammetry on low-volume (20 μL) screen-printed carbon electrodes (C-SPE) in ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((BMIM) TFSI). An easy and rapid washing treatment allowed us to obtain the resulting MIP film, directly used for tyr electrochemical detection, carried out amperometrically. The sensor showed a linear response in the concentration range of 15–200 μM, with LOD of 1.04 µM, LOQ of 3.17 μM and good performance in selectivity, stability, and reproducibility. Tyrosine amperometric detection was also carried out in human plasma, resulting in a satisfactory recovery estimation. The work represents the first use of BT2-T4 as a functional monomer for the production of a molecularly imprinted polymer, with a green approach afforded by using a few microliters of a room temperature ionic liquid as an alternative to common organic solvents on screen-printed carbon electrodes, resulting in a valuable system that meets the green chemistry guidelines, which is today an essential criterion in both research and application field.

Mycotoxins are toxic metabolites of molds which can contaminate food and beverages. Because of their acute and chronic toxicity, they can have harmful effects when ingested or inhaled, posing severe risks to human health. Contemporary analytical methods have the sensitivity required for contamination detection and quantification, but the direct application of these methods on real samples is not straightforward because of matrix complexity, and clean-up and preconcentration steps are needed, more and more requiring the application of highly selective solid-phase extraction materials. Molecularly imprinted polymers (MIPs) are artificial receptors mimicking the natural antibodies that are increasingly being used as a solid phase in extraction methods where selectivity towards target analytes is mandatory. In this review, the state-of-the-art about molecularly imprinted polymers as solid-phase extraction materials in mycotoxin contamination analysis will be discussed, with particular attention paid to the use of mimic molecules in the synthesis of mycotoxin-imprinted materials, to the application of these materials to food real samples, and to the development of advanced extraction methods involving molecular imprinting technology.

The aims of this study were to investigate the potential of utilising molecularly imprinted polycarbazole layers to detect highly toxic picric acid (PA) and to provide information about their performance. Quantum chemical calculations showed that strong interactions occur between PA and carbazole (bond energy of approximately 31 kJ/mol), consistent with the theoretical requirements for effective molecular imprinting. The performance of the sensors, however, was found to be highly limited, with the observed imprinting factor values for polycarbazole (PCz) layers being 1.77 and 0.95 for layers deposited on Pt and glassy carbon (GC) electrodes, respectively. Moreover, the molecularly imprinted polymer (MIP) layers showed worse performance than unmodified Pt or GC electrodes, for which the lowest limit of detection (LOD) values were determined (LOD values of 0.09 mM and 0.26 mM, respectively, for bare Pt and MIP PCz/Pt, as well as values of 0.11 mM and 0.57 mM for bare GC and MIP PCz/GC). The MIP layers also showed limited selectivity and susceptibility to interfering agents. An initial hypothesis on the reasons for such performance was postulated based on the common properties of conjugated polymers.

In this work, dopamine (DA) was polymerized on the surface of CuO nanoparticles (CuO NPs) to form a molecularly imprinted polymer (MIP@PDA/CuO NPs) for the colorimetric detection of astragaloside-IV (AS-IV). The synthesis process of MIP is simple and easy to operate, without adding other monomers or initiators. CuO NPs has high peroxidase (POD)-like activity that can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to generate oxidized TMB (OxTMB) in the presence of H2O2, having a maximum ultraviolet-visible (UV-Vis) absorption peak at 652 nm. The AS-IV can specifically bind to the surface imprinted cavities and prevent the entry of TMB and H2O2, which will lead to the inhibition of the catalytic reaction. Therefore, a new approach based on the POD-like activity of MIP@PDA/CuO NPs for AS-IV detection was developed with a linear range from 0.000341 to 1.024 mg/mL. The LOD and LOQ are 0.000991 and 0.000341 mg/mL, respectively. The developed method can accurately determine AS-IV in Huangqi Granules and different batches of Ganweikang Tablets, which are similar to the results measured by HPLC-ELSD and meet the requirements of Chinese Pharmacopoeia (2020 edition) for the amount of AS-IV in Huangqi Granules. The combination of MIP with CuO NPs not only endows the detection of AS-IV with high selectivity and reliability, but also expands the application of nanozymes in the detection of small-molecule compounds that have weak UV absorption, and do not have reducibility or oxidation properties.

The rapid, sensitive, and selective detection of pathogenic bacteria is of utmost importance in ensuring food safety and preventing the spread of infectious diseases. Here, we present a novel, reusable, and cost-effective impedimetric sensor based on a dual bacteria-imprinted polymer (DBIP) for the specific detection of Escherichia coli O157:H7 and Staphylococcus aureus. The DBIP sensor stands out with its remarkably short fabrication time of just 20 min, achieved through the efficient electro-polymerization of o-phenylenediamine monomer in the presence of dual bacterial templates, followed by in-situ template removal. The key structural feature of the DBIP sensor lies in the cavity-free imprinting sites, indicative of a thin layer of bacterial surface imprinting. This facilitates rapid rebinding of the target bacteria within a mere 15 min, while the sensing interface regenerates in just 10 min, enhancing the sensor’s overall efficiency. A notable advantage of the DBIP sensor is its exceptional selectivity, capable of distinguishing the target bacteria from closely related bacterial strains, including different serotypes. Moreover, the sensor exhibits high sensitivity, showcasing a low detection limit of approximately 9 CFU mL−1. The sensor’s reusability further enhances its cost-effectiveness, reducing the need for frequent sensor replacements. The practicality of the DBIP sensor was demonstrated in the analysis of real apple juice samples, yielding good recoveries. The integration of quick fabrication, high selectivity, rapid response, sensitivity, and reusability makes the DBIP sensor a promising solution for monitoring pathogenic bacteria, playing a crucial role in ensuring food safety and safeguarding public health.

This work reports the development and application of a highly selective core@shell-based quantum dot–molecularly imprinted polymer (QD@MIP) sensor for the detection of sulfadiazine (SDZ)—an antibiotic which belongs to the sulfonamide family. The synthesis of the smart material or MIP (molecularly imprinted polymer) was carried out by a precipitation method directly on the quantum dot surface, which played the role of a fluorescent probe in the optical sensor. The synthesized polymer was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Fluorescence experiments were performed in order to evaluate the effects of pH, interaction time of the QD@MIP with the analyte and SDZ concentration in different matrices. Under optimized conditions, a linear concentration range of 10.0–60.0 ppm and a limit of detection of 3.33 ppm were obtained. The repeatability and reproducibility of the proposed QD@MIP were evaluated in terms of the RSD, where RSD values of less than 5% were obtained in both tests. Selectivity studies were carried out in the presence of four possible interfering substances with quenching properties, and the signals obtained for these interferents confirmed the excellent selectivity of the proposed sensor; the imprinting factor value obtained for SDZ was 1.64. Finally, the proposed sensor was applied in real animal-based food samples using a spiked concentration of SDZ, where the recovery values obtained were above 90% (experiments were performed in triplicate).

Molecularly imprinted polymers (MIPs) and aptamers (Apts) are widely used in substance detection due to their specific recognition abilities. However, both of them have limitations in terms of stability or sensitivity. Therefore, an increasingly employed strategy is to combine MIPs and aptamers to form mixed components for detecting various substances, such as viruses, bacteria, proteins, heavy-metal ions, and hormones. The aim of this review is to provide a comprehensive summary of the scientific research conducted on the construction and application of aptamer–MIP multiple-recognition components in the past five years. It also aims to analyze their research and development strategies, construction mechanisms, advantages, and potential applications, as well as limitations and current challenges that need to be addressed.

Due to the release of hazardous heavy metals from various industries, water pollution has become one of the biggest challenges for environmental scientists today. Mercury Hg(II) is regarded as one of the most toxic heavy metals due to its ability to cause cancer and other health issues. In this study, a tailor-made modern eco-friendly molecularly imprinted polymer (MIP)/nanoporous carbon (NC) nanocomposite was synthesized and examined for the uptake of Hg(II) using an aqueous solution. The fabrication of the MIP/NC nanocomposite occurred via bulk polymerization involving the complexation of the template, followed by polymerization and, finally, template removal. Thus, the formed nanocomposite underwent characterizations that included morphological, thermal degradation, functional, and surface area analyses. The MIP/NC nanocomposite, with a high specific surface area of 884.9 m2/g, was evaluated for its efficacy towards the adsorptive elimination of Hg(II) against the pH solution changes, the dosage of adsorbent, initial concentration, and interaction time. The analysis showed that a maximum Hg(II) adsorption effectiveness of 116 mg/g was attained at pH 4, while the Freundlich model fitted the equilibrium sorption result and was aligned with pseudo-second-order kinetics. Likewise, thermodynamic parameters like enthalpy, entropy, and Gibbs free energy indicated that the adsorption was consistent with spontaneous, favorable, and endothermic reactions. Furthermore, the adsorption efficiency of MIP/NC was also evaluated against a real sample of condensate from the oil and gas industry, showing an 87.4% recovery of Hg(II). Finally, the synthesized MIP/NC showed promise as a selective adsorbent of Hg(II) in polluted environments, suggesting that a variety of combined absorbents of different precursors is recommended to evaluate heavy metal and pharmaceutical removals.

This paper presents a comprehensive investigation of the various parameters involved in the fabrication of a molecularly imprinted polymer (MIP) sensor for the detection of cortisol. Parameters such as monomer concentration, electropolymerization cycles, pH, monomer–template ratio, template removal technique, and rebinding time were optimized to establish a more consistent and effective method for the fabrication of MIP sensors. Under the optimized conditions, the MIP sensor demonstrated a proportional decrease in differential pulse voltammetry peak currents with increasing cortisol concentration in the range of 0.1 to 100 nM. The sensor exhibited excellent sensitivity, with a limit of detection of 0.036 nM. Selectivity experiments using a non-imprinted polymer sensor confirmed the specific binding affinity of the MIP sensor for cortisol, distinguishing it from other steroid hormones. This study provides crucial insights into the development of a reliable and sensitive strategy for cortisol detection using O-PD-based MIPs. These findings laid the foundation for further advancements in MIP research.

A new method for the determination of the antiplatelet drug dipyridamole (DIP) in pharmaceuticals using a molecularly imprinted polymer (MIP)-modified pencil graphite electrode (PGE) is proposed. The modified electrode was prepared simply and rapidly by electropolymerization of caffeic acid (CA) in the presence of DIP and subsequent DIP extraction with ethanol, resulting in a cost-effective, eco-friendly disposable modified electrode (MIP_PGE). Several working conditions (monomer and template concentration, number of voltametric cycles, scan rate extraction time, and solvent) for the MIP_PGE preparation were optimized. The differential pulse voltammetric (DPV) oxidation signal of DIP obtained at MIP_PGE was 28% higher than that recorded at bare PGE. Cyclic voltammetry emphasized DIP irreversible, pH-dependent, diffusion-controlled oxidation at MIP_PGE. Differential pulse and adsorptive stripping voltammetry at MIP_PGE in phosphate buffer solution pH = 7.00 were applied for the drug quantitative determination in the range of 1.00 × 10−7–1.00 × 10−5 and 1.00 × 10−8–5.00 × 10−7 mol/L DIP, respectively. The obtained limits of detection were at the tens nanomolar level.

Hybrid magnetic molecularly imprinted polymers (MMIPs) have the advantages of the technology of molecularly imprinted material and magnetic nanoparticles. The magnetic properties of MMIPs allow easy magnetic separation of various pollutants and analytes. A convenient and simple approach has been developed for the preparation of MMIPs based on polyamide (nylon-6) and magnetic nanoparticles. The polymer matrix was formed during the transition of nylon-6 from a dissolved state to a solid state in the presence of template molecules and Fe3O4 nanoparticles in the initial solution. Methylene blue (MB) was used as a model imprinted template molecule. The MMIPs exhibited a maximum adsorption amount of MB reached 110 µmol/g. The selectivity coefficients toward MB structural analogs were estimated to be 6.1 ± 0.6 and 2.1 ± 0.3 for 15 μM hydroxyethylphenazine and toluidine blue, which shows high MMIP selectivity. To prove the MMIPs’ specificity in MB recognition, magnetic nonimprinted polymers (MNIPs) were synthesized without the presence of a template molecule. MMIPs exhibited much higher specificity in comparison to MNIPs. To show the remarkable reusability of the MMIP sorbent, more than four MB absorption and release cycles were carried out, demonstrating almost the same extraction capacity step by step. We believe that the proposed molecular imprinting technology, shown in the MB magnetic separation example, will bring new advances in the area of MMIPs for various applications.

Developing sensitive and effective methods to monitor oxytetracycline residues in food is of great significance for maintaining public health. Herein, a fluorescent sensor (NH2-UIO-66 (Zr)@MIP) based on a molecularly imprinted polymer-coated amino-functionalized zirconium (IV) metal–organic framework was successfully constructed and first used for the ultrasensitive determination of oxytetracycline. NH2-UIO-66 (Zr), with a maximum emission wavelength of 455 nm under 350 nm excitation, was prepared using a microwave-assisted heating method. The NH2-UIO-66 (Zr)@MIP sensor with specific recognition sites for oxytetracycline was then acquired by modifying a molecularly imprinted polymer on the surface of NH2-UIO-66 (Zr). The introduction of NH2-UIO-66 (Zr) as both a signal tag and supporter can strengthen the sensitivity of the fluorescence sensor. Thanks to the combination of the unique characteristics of the molecularly imprinted polymer and NH2-UIO-66 (Zr), the prepared sensor not only exhibited a sensitive fluorescence response, specific identification capabilities and a high selectivity for oxytetracycline, but also showed good fluorescence stability, satisfactory precision and reproducibility. The fabricated sensor displayed a fluorescent linear quenching in the OTC concentration range of 0.05–40 μg mL−1, with a detection limit of 0.012 μg mL−1. More importantly, the fluorescence sensor was finally applied for the detection of oxytetracycline in milk, and the results were comparable to those obtained using the HPLC approach. Hence, the NH2-UIO-66 (Zr)@MIP sensor possesses great application potential for the accurate evaluation of trace oxytetracycline in dairy products.

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine—one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

Polyfluoroalkyl compounds (PFASs) are synthetic compounds recently classified as permanent and emerging chemicals ever since their bioaccumulation in humans and the environment, due to the presence of carbon–fluorine functional groups. The design of novel screening tools with addressed high response time for the routine quantification of PFASs in water is highly desirable. In this work, we propose the preparation of a new voltammetric sensor based on molecularly imprinted polymer nanoparticle (nanoMIP) receptors for the highly sensitive and selective quantification of PFASs in water. The nanoMIPs were synthesized by the solid phase approach and immobilized onto functionalized screen-printed platinum electrode (SPPtE), chosen as the transduction element for sensor development. Dimensional characterization of nanoMIPs by Dynamic light scattering (DLS) shows small nanosized imprinted particles (

A novel, molecularly imprinted, upconversion fluorescence probe (UCNP@MIFP) for sulfonamide sensing was fabricated by Pickering emulsion polymerization using UCNP@SiO2 particles as the stabilizer and sulfamethazine/sulfamerazine as the co-templates. The synthesis conditions of the UCNP@MIFP were optimized, and the synthesized probe was characterized by scanning electron microscopy, Fourier transform infrared spectrometer, thermogravimetric analyzer, and fluorescence spectrometer. The UCNP@MIFPs showed a good adsorption capacity and a fast kinetic feature for the template. The selectivity experiment revealed that the UCNP@MIFP has a broad-spectrum molecular recognition capability. Good linear relationships were obtained over the concentration range of 1–10 ng/mL for sulfamerazine, sulfamethazine, sulfathiazole, and sulfafurazole, with low limits of detection in the range of 1.37–2.35 ng/mL. The prepared UCNP@MIFP has the potential to detect four sulfonamide residues in food and environmental water.

Interfacing recognition materials with transducers has consistently presented a challenge in the development of sensitive and specific chemical sensors. In this context, a method based on near-field photopolymerization is proposed to functionalize gold nanoparticles, which are prepared by a very simple process. This method allows in situ preparation of a molecularly imprinted polymer for sensing by surface-enhanced Raman scattering (SERS). In a few seconds, a functional nanoscale layer is deposited by photopolymerization on the nanoparticles. In this study, the dye Rhodamine 6G was chosen as a model target molecule to demonstrate the principle of the method. The detection limit is 500 pM. Due to the nanometric thickness, the response is fast, and the substrates are robust, allowing regeneration and reuse with the same performance level. Finally, this method of manufacturing has been shown to be compatible with integration processes, allowing the future development of sensors integrated in microfluidic circuits and on optical fibers.

Developing an efficient method for chloramphenicol (CAP) detection is of great significance for food safety. Arginine (Arg) was selected as a functional monomer. Benefiting from its excellent electrochemical performance, which is different from traditional functional monomers, it can be combined with CAP to form a highly selective molecularly imprinted polymer (MIP) material. It overcomes the shortcoming of poor MIP sensitivity faced by traditional functional monomers, and achieves high sensitivity detection without compounding other nanomaterials, greatly reducing the preparation difficulty and cost investment of the sensor. The possible binding sites between CAP and Arg molecules were calculated by molecular electrostatic potential (MEP). A low-cost, non-modified MIP electrochemical sensor was developed for the high-performance detection of CAP. The prepared sensor has a wide linear range from 1 × 10−12 mol L−1 to 5 × 10−4 mol L−1, achieves a very low concentration CAP detection, and the detection limit is 1.36 × 10−13 mol L−1. It also exhibits excellent selectivity, anti-interference, repeatability, and reproducibility. The detection of CAP in actual honey samples was achieved, which has important practical value in food safety.

Molecularly imprinted polymers (MIPs) have been widely utilized in the field of sensing due to their specific and high affinity towards target molecules. Combining the selective preconcentration capability of MIPs and the rapid quantitation merit of optical analytical techniques, MIP optical sensors have been applied to the analysis of various kinds of samples and have received considerable attention in recent years. In this review, we overviewed the progress of MIP sensors in combination with various optical detection methods, including fluorescence, surface plasmon resonance, Raman scattering, and chemiluminescence. The construction, characterization, working principle, and application of four kinds of MIP optical sensors are covered in detail. Finally, the opportunities and challenges currently encountered by MIP optical sensors are summarized.

Surface imprinting used for protein recognition in functional cavities is highly effective in imprinting biomacromolecules to avoid template encapsulation during the formation of a molecularly imprinted polymer (MIP) matrix. Herein, we introduce a facile surface-imprinting method based on two-step spin-coating and photopolymerization to design highly efficient imprinted sites on polymeric films to detect trypsin (TRY). Well-distributed template imprinting is successfully achieved for maximized sensing responses by controlling the composition of functional monomers and crosslinkers in the precursor solution and the concentration of TRY in the imprinting solution. The MIP film exhibits higher sensitivity (−841 ± 65 Hz/(μg/mL)) with a coefficient of determination of 0.970 and a higher imprinting factor of 4.5 in a 0.24 µg/mL TRY solution compared to the nonimprinted polymer (NIP) film. Moreover, the limit of detection and limit of quantification are calculated to be 25.33 and 84.42 ng/mL, respectively. Finally, the selectivity coefficient is within the range of 3.90–6.78 for TRY against other proteins. These sensing properties are superior to those of the corresponding nonimprinted polymer matrix. Thus, the proposed facile surface-imprinting method is highly effective for protein imprinting with high sensitivity and selectivity.

Molecularly imprinted polymer (MIP)-based luminescent chemosensors combine the advantages of the highly specific molecular recognition of the imprinting sites and the high sensitivity with the luminescence detection. These advantages have drawn great attention during the past two decades. Luminescent molecularly imprinted polymers (luminescent MIPs) towards different targeted analytes are constructed with different strategies, such as the incorporation of luminescent functional monomers, physical entrapment, covalent attachment of luminescent signaling elements on the MIPs, and surface-imprinting polymerization on the luminescent nanomaterials. In this review, we will discuss the design strategies and sensing approaches of luminescent MIP-based chemosensors, as well as their selected applications in biosensing, bioimaging, food safety, and clinical diagnosis. The limitations and prospects for the future development of MIP-based luminescent chemosensors will also be discussed.

This study investigates biomimetic sensors for the detection of methotrexate contaminants in environmental samples. Sensors inspired by biological systems are the focus of this biomimetic strategy. Methotrexate is an antimetabolite that is widely used for the treatment of cancer and autoimmune diseases. Due to the widespread use of methotrexate and its rampant disposal into the environment, the residues of this drug are regarded as an emerging contaminant of huge concern, considering that exposure to the contaminant has been found to lead to the inhibition of some essential metabolic processes, posing serious risks to humans and other living beings. In this context, this work aims to quantify methotrexate through the application of a highly efficient biomimetic electrochemical sensor constructed using polypyrrole−based molecularly imprinted polymer (MIP) electrodeposited by cyclic voltammetry on a glassy carbon electrode (GCE) modified with multi−walled carbon nanotubes (MWCNT). The electrodeposited polymeric films were characterized by infrared spectrometry (FTIR), scanning electron microscopy (SEM), and cyclic voltammetry (CV). The analyses conducted using differential pulse voltammetry (DPV) yielded a detection limit of 2.7 × 10−9 mol L−1 for methotrexate, a linear range of 0.01–125 μmol L−1, and a sensitivity of 0.152 μA L mol−1. The results obtained from the analysis of the selectivity of the proposed sensor through the incorporation of interferents in the standard solution pointed to an electrochemical signal decay of only 15.4%. The findings of this study show that the proposed sensor is highly promising and suitable for use in the quantification of methotrexate in environmental samples.

A novel and environmentally friendly molecularly imprinted polymer (PCA-MIP) was successfully synthesized in an aqueous solution for the selective extraction of protocatechuic acid (PCA). In this study, a deep eutectic solvent (DES, choline chloride/methacrylic acid, 1:2, mol/mol) and chitosan were employed as the eco-friendly functional monomers. These two components interacted with PCA through hydrogen bonding, integrating a multitude of recognition sites within the PCA-MIP. Thus, the resulting PCA-MIP exhibited outstanding adsorption performance, rapid adsorption rate, and better selectivity, with a maximum binding capacity of 30.56 mg/g and an equilibrium time of 30 min. The scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET) analyses revealed that the synthesized polymers possessed a uniform morphology and substantial surface areas, which were conducive to their adsorption properties. Moreover, the PCA-MIP integrated with HPLC demonstrated its efficacy as an adsorbent for the selective extraction of PCA from mango juice. The PCA-MIP presented itself as an exemplary adsorbent, offering a highly effective and eco-friendly method for the enrichment of PCA from complex matrices.

To protect consumers from risks related to overexposure to sulfadiazine, total residues of this antibacterial agent in animal-origin foodstuffs not exceed international regulations. To this end, a new electrochemical sensor based on a molecularly imprinted polymer nanocomposite using overoxidized polypyrrole and copper nanoparticles for the detection of sulfadiazine is elaborated. After optimization of the preparation of the electrochemical sensors, their differential pulse voltammetric signal exhibits an excellent stability and reproducibility at 1.05 V, with a large linear range between 10−9 and 10−5 mol L−1 and a low detection limit of 3.1 × 10−10 mol L−1. The produced sulfadiazine sensor was successfully tested in real milk samples. The combination of the properties of the electrical conduction of copper nanoparticles with the properties of the preconcentration of the molecularly imprinted overoxidized polypyrrole allows for the highly sensitive detection of sulfadiazine, even in real milk samples. This strategy is new and leads to the lowest detection limit yet achieved, compared to those of the previously published sulfadiazine electrochemical sensors.

In general, volatile organic compounds (VOCs) have a high vapor pressure at room temperature (RT). It has been reported that all humans generate unique VOC profiles in their exhaled breath which can be utilized as biomarkers to diagnose disease conditions. The VOCs available in exhaled human breath are the products of metabolic activity in the body and, therefore, any changes in its control level can be utilized to diagnose specific diseases. More than 1000 VOCs have been identified in exhaled human breath along with the respiratory droplets which provide rich information on overall health conditions. This provides great potential as a biomarker for a disease that can be sampled non-invasively from exhaled breath with breath biopsy. However, it is still a great challenge to develop a quick responsive, highly selective, and sensitive VOC-sensing system. The VOC sensors are usually coated with various sensing materials to achieve target-specific detection and real-time monitoring of the VOC molecules in the exhaled breath. These VOC-sensing materials have been the subject of huge interest and extensive research has been done in developing various sensing tools based on electrochemical, chemoresistive, and optical methods. The target-sensitive material with excellent sensing performance and capturing of the VOC molecules can be achieved by optimizing the materials, methods, and its thickness. This review paper extensively provides a detailed literature survey on various non-biological VOC-sensing materials including metal oxides, polymers, composites, and other novel materials. Furthermore, this review provides the associated limitations of each material and a summary table comparing the performance of various sensing materials to give a better insight to the readers.

2,4-Dichlorophenoxyacetic acid (2,4-D) is a widely used herbicide worldwide. However, its residues in agricultural products are extremely harmful to human health and to the environment in soil and water. Previous methods for determining 2,4-D in water and soil samples are expensive, cumbersome, and not highly selective. In this study, we developed a novel disposal sensor based on screen-printed electrodes (SPEs) for detecting 2,4-D in wastewater and soil samples. The SPEs were modified with conductive polyaniline (PANI) layer and polyvinyl chloride (PVC) membrane loaded with molecularly printed polymer (MIP). The MIP particles were prepared using 2,4-D as template, methacrylic acid (MAA) as monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, and benzoyl peroxide as initiator. The best sensor shows a dynamic concentration range of 10−2 to 10−7 M 2,4-D, a detection limit (LOD) of 3.6 × 10−7 M, Nernst slope (response) of 29.9 mV/decade, and high selectivity over other interfering species previously reported in the literature. The sensors also achieved a short response time of 25 s, high reversibility, and a lifetime of over 2 weeks. The developed sensors were successfully used for determining 2,4-D in real wastewater and soil samples with high accuracy and precision.

A new molecularly imprinted electrochemical sensor was proposed to determine 4,4′-methylene diphenyl diamine (MDA) using molecularly imprinted polymer–multiwalled carbon nanotubes modified glassy carbon electrode (MIP/MWCNTs/GCE). GCE was coated by MWCNTs (MWCNTs/GCE) because of their antifouling qualities and in order to improve the sensor sensitivity. To make the whole sensor, a polymeric film made up of chitosan nanoparticles was electrodeposited by the cyclic voltammetry method on the surface of MWCNTs/GCE in the presence of MDA as a template. Different parameters such as scan cycles, elution time, incubation time, molar ratio of template molecules to functional monomers, and pH were optimized to increase the performance of the MIP sensor. With a detection limit of 15 nM, a linear response to MDA was seen in the concentration range of 0.5–100 µM. The imprinting factor (IF) of the proposed sensor was also calculated at around 3.66, demonstrating the extremely high recognition performance of a MIP/MWCNT-modified electrode. Moreover, the sensor exhibited good reproducibility and selectivity. Finally, the proposed sensor was efficiently used to determine MDA in real samples with satisfactory recoveries ranging from 94.10% to 106.76%.

As a steroid hormone, cortisol has a close relationship with the stress response, and therefore, can be used as a biomarker for early detection of stress. An electrochemical immunosensor is one of the most widely used methods to detect cortisol, with antibodies as its bioreceptor. Apart from conventional laboratory-based methods, the trend for cortisol detection has seemed to be exploiting antibodies and aptamers. Both can provide satisfactory performance with high selectivity and sensitivity, but they still face issues with their short shelf life. Molecularly imprinted polymers (MIPs) have been widely used to detect macro- and micro-molecules by forming artificial antibodies as bioreceptors. MIPs are an alternative to natural antibodies, which despite demonstrating high selectivity and a low degree of cross-reactivity, often also show a high sensitivity to the environment, leading to their denaturation. MIPs can be prepared with convenient and relatively affordable fabrication processes. They also have high durability in ambient conditions, a long shelf life, and the ability to detect cortisol molecules at a concentration as low as 2 ag/mL. By collecting data from the past five years, this review summarizes the antibody and aptamer-based amperometric sensors as well as the latest developments exploiting MIPs rather than antibodies. Lastly, factors that can improve MIPs performance and are expected to be developed in the future are also explained.

A novel potentiometric microelectrode incorporating a molecularly imprinted polymer (MIP) was fabricated, characterized, and successfully applied to the recognition and quantification of the drug, metronidazole benzoate. The elaborated MIP-based sensor was realized by thermal polarization, using metronidazole benzoate as the template material, 1-vinyl-2-pyrrolidine (VP) as a functional monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent in the presence of benzoyl peroxide as the initiator. The MIP-based sensor exhibited a super-Nernstian response (61.5 ± 0.5, mV/decade) covering the linear concentration range of 1 × 10−8–1 × 10−3 mole L−1 of metronidazole benzoate with a fast response time (≤10, s.) and detection limit of 7 × 10−9 mole L−1. The microchip showed high selectivity toward the template drug molecule in the presence of many investigated interfering species. The chip electrode was successfully used in the quantification of metronidazole benzoate in some real biological samples with high accuracy (recovery, 95.4%) and precision (RSD, 1.5). Moreover, the merits offered by the elaborated MIP-based MB microchip assembly include small size, miniaturization, integration, and consequently, automation feasibility.

Caffeic acid (CA) is an efficient antioxidant found in wine and in plants and can be extracted from the by-products of the food industry. A molecularly imprinted polymer specific to caffeic acid (CA-MIP) was prepared by radical polymerization using N-phenylacrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and azobisisobutyronitrile as the initiator, in the presence of CA as the template molecule. The rebinding activities between the polymers and CA were promoted by an indirect method and characterized by cyclic voltammetry (CV) using a screen-printed carbon electrode (SPCE). It is a fast method, which only requires simple and portable instrumentation. The polymer showed a high selectivity toward CA and a good repeatability. CA-MIP was then applied in wine samples spiked with CA, and the results were compared to those obtained by a chromatographic method. With a limit of detection of 0.06 mM in wine, the recovery values confirmed that the method is suitable for further applications.

An electrochemical sensor based on a molecularly imprinted polymer membrane (MIP) was developed. The electrochemical sensor was prepared by electropolymerization of o-phenylenediamine (O-PD) on the surface of glassy carbon electrode (GCE), modified by AuNPs@covalent organic framework (COF) microspheres with ascorbic acid (AA) as template molecule. First, ultrasmall polyvinylpyrrolidone (PVP)-coated AuNPs were prepared by a chemical reduction method. Then, 1,3,5-tri(p-formylphenyl)benzene (TFPB) and N-boc-1,4-phenylene diamine (NBPDA) underwent an ammonaldehyde condensation reaction on PVP-coated AuNPs to form AuNPs@COFTFPB-NBPDA microspheres. The porous spherical structure of AuNPs@ COFTFPB-NBPDA could accelerate the mass transfer, enlarge the specific surface area, and enhance the catalytic activity of PVP-coated AuNPs. The electrochemical sensors, based on AuNPs@ COFTFPB-NBPDA/GCE and nMIPs/AuNPs@COFTFPB-NBPDA/GCE, were applied for the detection of AA, with a detection limit of 1.69 and 2.57 μM, as well as linear ranges of 5.07 to 60 mM and 7.81 to 60 mM. The nMIPs/AuNPs@COFTFPB-NBPDA sensor had satisfactory stability, selectivity, and reproducibility for AA detection.

Lysozyme (LYS) applications encompass anti-bacterial activity, analgesic, and anti-inflammatory effects. In this work, a porous framework that was based on the polymerization of pyrrole (PPy) in the presence of multi-functional graphene oxide/iron oxide composite (GO@Fe3O4) has been developed. Oxygen-containing and amine groups that were present in the nanocomposite were availed to assembly LYS as the molecularly imprinted polymer (MIP) template. The synthesized material (MIPPy/GO@Fe3O4) was electrodeposited on top of a gold microelectrode array. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to confirm the adequate preparation of GO@Fe3O4, and the characterization of the resulting molecularly imprinted electrochemical sensor (MIECS) was carried out by electrochemical impedance spectrometry (EIS), FT-IR analysis, and scanning electron microscopy (SEM). The impedimetric responses were analyzed mathematically by fitting to a Q(Q(RW)) equivalent circuit and quantitative determination of LYS was obtained in a linear range from 1 pg/mL to 0.1 µg/mL, presenting good precision (RSD ≈ 10%, n = 5) and low limit of detection (LOD = 0.009 pg/mL). The fabrication of this device is relatively simple, scalable, rapid, and economical, and the sensor can be used up to nine times without disintegration. The MIECS was successfully applied to the determination of LYS in fresh chicken egg white sample and in a commercial drug, resulting in a straightforward platform for the routine monitoring of LYS.

Molecularly imprinted polymers (MIPs) are widely used as modifiers in electrochemical sensors due to their high sensitivity and promise of inexpensive mass manufacturing. Here, we propose and demonstrate a novel MIP-sensor that can measure the electrochemical activity of favipiravir (FAV) as an antiviral drug, thereby enabling quantification of the concentration of FAV in biological and river water samples and in real-time. MOF nanoparticles’ application with various shapes to determine FAV at nanomolar concentrations was described. Two different MOF nanoparticle shapes (dodecahedron and sheets) were systematically compared to evaluate the electrochemical performance of FAV. After carefully examining two different morphologies of MIP-Co-Ni@MOF, the nanosheet form showed a higher performance and efficiency than the nanododecahedron. When MIP-Co/Ni@MOF-based and NIP-Co/Ni@MOF electrodes (nanosheets) were used instead, the minimum target concentrations detected were 7.5 × 10−11 (MIP-Co-Ni@MOF) and 8.17 × 10−9 M (NIP-Co-Ni@MOF), respectively. This is a significant improvement (>102), which is assigned to the large active surface area and high fraction of surface atoms, increasing the amount of greater analyte adsorption during binding. Therefore, water-dispersible MIP-Co-Ni@MOF nanosheets were successfully applied for trace-level determination of FAV in biological and water samples. Our findings seem to provide useful guidance in the molecularly imprinted polymer design of MOF-based materials to help establish quantitative rules in designing MOF-based sensors for point of care (POC) systems.

The most challenging step in developing bioanalytical methods is finding the best sample preparation method. The matrix interference effect of biological sample become a reason of that. Molecularly imprinted SERS become a potential analytical method to be developed to answer this challenge. In this article, we review recent progress in MIP SERS application particularly in bioanalysis. Begin with the explanation about molecular imprinting technique and component, SERS principle, the combination of MIP SERS, and follow by various application of MIP SERS for analysis. Finally, the conclusion and future perspective were also discussed.

Alcoholic beverages contaminated with scopolamine (SCP) are often employed for criminal purposes due to their sedative effect. The determination of the residual levels of SCP in body fluids (e.g., urine) can help to track possible victims of induced ingestions. Biological sample analysis usually requires a preconcentration step to enhance their detectability and to provide sample clean-up. Molecularly imprinted polymers (MIPs) in lieu of conventional solid sorbents represent an enhancement of selectivity, due to their specific recognition sites. Additionally, the adaptation of the solid-phase extraction (SPE) cartridge into a disposable pipette tip extraction (DPX) contributes to the miniaturization of the sample preparation step. Herein, an analytical method for the determination of SCP in synthetic urine samples via the integration of molecularly imprinted solid-phase extraction (MISPE) with DPX as a preconcentration step prior to capillary electrophoresis analysis (also known as MISPE-DPX-CE) is presented. The extraction and elution steps were optimized using a factorial design. Using the optimized conditions, a preconcentration factor of 20 was obtained, leading to a working range of 0.5–6 µM with LOD of 0.04 µM and repeatability of 6.4% (n = 7) and adequate recovery values (84 and 101%) The proposed MISPE-DPX-CE approach was successfully applied to selective extraction, preconcentration, and determination of SCP in synthetic urine samples.

Biochips are composed of arrays of micropatterns enabling the optical detection of target analytes. Inkjet printing, complementary to commercially available micro- and nanospotters, is a contactless and versatile micropatterning method. Surprisingly, the inkjet printing of molecularly imprinted polymers (MIPs), also known as biomimetic synthetic antibodies, has not been demonstrated as yet. In this work, core–shell structures are proposed through the combination of inkjet printing of the core (top-down approach) and controlled radical polymerization (CRP) to decorate the core with a thin film of MIP (bottom-up approach). The resulting biochips show quantitative, specific, and selective detection of antibiotic drug enrofloxacin by means of fluorescence analysis.

Recent advances have allowed the monitoring of several volatile organic compounds (VOCs) in human exhaled breath, and many of them are being utilized as a biomarker to diagnose several diseases, including diabetes. Among several VOCs, isopropanol (IPA) has been reported as a common volatile compound in the exhaled breath of patients with type 1 and type 2 diabetes. In this article, an experimental approach is discussed to develop a highly selective and sensitive IPA vapor sensor system. The fabricated sensor is comprised of a small and portable glass slide coated with molecularly imprinted polymer containing specific binding sites compatible with IPA molecules. The developed sensor is based on the wavelength interrogation technique. The fabricated device is analyzed for the detection of IPA vapor with different concentrations varying from 50% to 100%. The sensor exhibits maximum sensitivities of 0.37, 0.30, and 0.62 nm/%IPA, respectively, for 30, 60, and 90 min, respectively, and an excellent sensitivity of 0.63 nm/%IPA for 120 min exposure along with good selectivity among a similar class of VOCs. The major features of the sensor i.e., small size, portability, cost-effectiveness, high sensitivity, and good selectivity, make it a potential candidate for diabetes monitoring. The promising results of the sensor illustrate its potential in diabetes monitoring applications.

Paper-based analytical devices (PADs) are highly effective tools due to their low cost, portability, low reagent accumulation, and ease of use. Molecularly imprinted polymers (MIP) are also extensively used as biomimetic receptors and specific adsorption materials for capturing target analytes in various complex matrices due to their excellent recognition ability and structural stability. The integration of MIP and PADs (MIP-PADs) realizes the rapid, convenient, and low-cost application of molecular-imprinting analysis technology. This review introduces the characteristics of MIP-PAD technology and discusses its application in the fields of on-site environmental analysis, food-safety monitoring, point-of-care detection, biomarker detection, and exposure assessment. The problems and future development of MIP-PAD technology in practical application are also prospected.

Molecular imprinting–aptamer techniques exhibit the advantages of molecular imprinting and aptamer technology. Hybrids of molecularly imprinted polymer–aptamer (MIP–aptamer) prepared by this technique have higher stability, binding affinity and superior selectivity than conventional molecularly imprinted polymers or aptamers. In recent years, molecular imprinting–aptamer technologies have attracted considerable interest for the selective recognition of target molecules in complex sample matrices and have been used in molecular recognition such as antibiotics, proteins, viruses and pesticides. This review introduced the development of molecular imprinting–aptamer-combining technologies and summarized the mechanism of MIP–aptamer formation. Meanwhile, we discussed the challenges in preparing MIP–aptamer. Finally, we summarized the application of MIP–aptamer to the molecular recognition in disease diagnosis, environmental analysis, food safety and other fields.

The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24% of SLX in spiked serum and 92.25 ± 1.12% when SLX was spiked with another analogue structure. Compared with the standard solid phase extraction sorbent C-18, which had a recovery of 79.11 ± 2.96%, the MIP showed better performance. The harmony between the simulation and experimental results illustrates that the molecular dynamic simulations had a significant role in the study and development of the MIPs for analysis of SLX in biological fluid.

Antibiotics are antibacterial agents applied in human and veterinary medicine. They are also employed to stimulate the growth of food-producing animals. Despite their benefits, the uncontrolled use of antibiotics results in serious problems, and therefore their concentration levels in different foods as well as in environmental samples were regulated. As a consequence, there is an increasing demand for the development of sensitive and selective analytical tools for antibiotic reliable and rapid detection. These requirements are accomplished by the combination of simple, cost-effective and affordable electroanalytical methods with molecularly imprinted polymers (MIPs) with high recognition specificity, based on their “lock and key” working principle, used to modify the electrode surface, which is the “heart” of any electrochemical device. This review presents a comprehensive overview of MIP-modified carbon-based electrodes developed in recent years for antibiotic detection. The MIP preparation and electrode modification procedures, along with the performance characteristics of sensors and analytical methods, as well as the applications for the antibiotics’ quantification from different matrices (pharmaceutical, biological, food and environmental samples), are discussed. The information provided by this review can inspire researchers to go deeper into the field of MIP-modified sensors and to develop efficient means for reliable antibiotic determination.

In this study, a novel fluorescent molecularly imprinted nanosensor (N, S-GQDs@ZIF-8@MIP) based on the nitrogen and sulfur co-doped graphene quantum dots decorated zeolitic imidazolate framework-8 was constructed for the detection of octopamine (OA). Herein, ZIF-8 with a large surface area was introduced as a supporter of the sensing system, which effectively shortened the response time of the sensor. Meanwhile, high green luminescent N, S-GQDs and a maximum emission wavelength of 520 nm under 460 nm excitation and a 12.5% quantum yield were modified on the surface of ZIF-8 as a signal tag that can convert the interactions between the sensor and OA into detectable fluorescent signals. Finally, N, S-GQDs@ZIF-8@MIP was acquired through the surface molecular imprinting method. Due to the synergy of N, S-GQDs, ZIF-8, and MIP, the obtained sensor not only demonstrated higher selectivity and sensitivity than N, S-GQDs@ZIF-8@NIP, but also displayed faster fluorescence response than N, S-GQDs@MIP. Under optimal conditions, the developed sensor presented a favorable linear relationship in the range of 0.1–10 mg L−1 with a detection limit of 0.062 mg L−1. Additionally, the proposed N, S-GQDs@ZIF-8@MIP strategy was effectively applied to the detection of OA in fermented samples, and the obtained results had a satisfactory correlation with those of HPLC.

A tryptophan (Trp) sensor was investigated based on electrochemical impedance spectroscopy (EIS) of a molecularly imprinted polymer on a lysozyme amyloid fibril (MIP-AF). The MIP-AF was composed of aniline as a monomer chemically polymerized in the presence of a Trp template molecule onto the AF surface. After extracting the template molecule, the MIP-AF had cavities with a high affinity for the Trp molecules. The obtained MIP-AF demonstrated rapid Trp adsorption and substantial binding capacity (50 µM mg−1). Trp determination was studied using non-Faradaic EIS by drop drying the MIP-AF on the working electrode of a screen-printed electrode. The MIP-AF provided a large linear range (10 pM–80 µM), a low detection limit (8 pM), and high selectivity for Trp determination. Furthermore, the proposed method also indicates that the MIP-AF can be used to determine Trp in real samples such as milk and cancer cell media.

Metal-organic frameworks (MOFs) with systematically tailored structures have been suggested as promising precursors to the preparation of diverse functional materials. Herein, a facile and versatile layer-by-layer strategy without any special surface modifications has been proposed for the preparation of magnetic metal-organic frameworks (MMOFs) supported molecularly imprinted polymer nanoparticles (MMOFs@MIP), which are based on a magnetically susceptible core conjugated with an imidazole-derived self-assembled layer and a silane-based imprinted shell. The obtained MMOFs@MIPs, which integrated the advantages of Fe3O4, MOFs, and MIPs, were characterized and exhibited good magnetic properties, a rapid mass transfer rate, and an excellent adsorption selectivity as well as capacity for the targeted molecular - bisphenol A (BPA). Moreover, the MMOFs@MIPs were employed as adsorbents in magnetic solid phase extraction (MSPE) to selectively bind and rapidly separate BPA from real samples with satisfactory recoveries ranging from 88.3% to 92.3%. More importantly, the desirable reusability of MMOFs@MIP was also evaluated, and the recoveries still maintained above 88.0% even after five re-use cycles. Furthermore, combined with high-performance liquid chromatography (HPLC) analysis, a novel MSPE-HPLC method was developed, enabling the highly selective and sensitive detection of BPA in a wide linear range of 0.5–5000 μg L−1 with a low limit of detection (LOD) of 0.1 μg L−1. This work contributes a promising method for constructing various functional nanoparticles @MOFs@MIP hybrid materials for applications in many different fields.