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The scarcity of selective adsorbents for efficient extraction and removal of microcystins (MCs) from complex samples greatly limits the precise detection and effective control of MCs. Three-dimensional covalent organic frameworks (3D COFs), characterized by their large specific surface areas and highly ordered rigid structure, are promising candidates, but suffer from lack of specific recognition. Herein, we design to engineer molecularly imprinted cavities within 3D COFs via molecularly imprinted technology, creating a novel adsorbent with exceptional selectivity, kinetics and capacity for the efficient extraction and removal of MCs. As proof-of-concept, a new CC bond-containing 3D COF, designated JNU-7, is designed and prepared for copolymerization with methacrylic acid, the pseudo template L-arginine and ethylene dimethacrylate to yield the JNU-7 based molecularly imprinted polymer (JNU-7-MIP). The JNU-7-MIP exhibits a great adsorption capacity (156 mg g -1 ) for L-arginine. Subsequently, the JNU-7-MIP based solid-phase extraction coupled with high performance liquid chromatography-mass spectrometry achieves low detection limit of 0.008 ng mL -1 , wide linear range of 0.025-100 ng mL -1 , high enrichment factor of 186, rapid extraction of 10 min, and good recoveries of 92.4%-106.5% for MC-LR. Moreover, the JNU-7-MIP can rapidly remove the MC-LR from 1 mg L -1 to levels (0.26-0.35 μg L -1 ) lower than the WHO recommended limit for drinking water (1 μg L -1 ). This work reveals the considerable potential of 3D COF based MIPs as promising adsorbents for the extraction and removal of contaminants in complex real samples., 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.)

As an emerging porous material, hydrogen-bonded organic framework materials (HOFs) still pose application challenges. In this work, the designed type "I + II" heterojunction extracted hot electrons from HOFs using quantum dots (QDs) and polypyrrole (Ppy), improving the stability and photoelectrochemical performance of materials. In addition to serving as a potential well, electropolymerized Ppy was used as a recognition element for bisphenol A (BPA), and a novel self-powered molecularly imprinted photoelectrochemical (MIP-PEC) sensor was designed. The sensing platform showed a linear relationship from 1 × 10 -10 to 1 × 10 -7 mol∙L -1 and from 1 × 10 -7 to 1 mol∙L -1 with an acceptable detection limit of 4.2 × 10 -11 mol∙L -1 . This is the first application of HOFs in constructing MIP-PEC sensors and a new attempt to improve the stability of HOFs for the application of porous crystal materials in the sensing field., 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 Ltd. All rights reserved.)

A novel metal-organic framework (MOF)/covalent-organic framework (COF) heterostructure hybrid composite (NH 2 -UiO-66/TpPa-1-COF) with excellent photoactivity was developed, which further acted as the photoelectrochemical sensitized layer of a molecularly imprinted photoelectrochemical (MIP-PEC) sensor for extremely sensitive and selective determination of dibutyl phthalate (DBP). The NH 2 -UiO-66/TpPa-1-COF was synthesized using a simple one-step solvothermal method, which showed improved photocurrent response owing to heterojunction formation, favorable energy-band configuration and strong light absorption capacity. To improve the sensing performance, molecularly imprinted polymer (MIP) was developed by sol-gel polymerization method as the recognition component of PEC sensor. The specific binding of imprinting sites towards DBP could block the electron transfer, causing decreased photocurrent response of the MIP-PEC sensor. The MIP-PEC sensor showed a wide detection range from 0.1 nmol L -1 to 100 μmol L -1 with a limit of detection of 3.0 × 10 -11  mol L -1 under optimal conditions. Meanwhile, the proposed MIP-PEC sensor showed good stability, selectivity, reproducibility, and applicability in real samples. This is the first attempt to apply MOF/COF heterostructure hybrid composite for MIP-PEC sensor construction, providing new insight into the potential applications of microporous crystalline framework heterostructure hybrid composite in the sensing field., 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 © 2022 Elsevier B.V. All rights reserved.)

In this study, for the first time, surface molecularly imprinted magnetic covalent organic frameworks (Fe 3 O 4 @COFs@MIPs) were combined with disposable screen-printed electrode (SPE) to construct a portable and on-site electrochemical sensor for the rapid detection of tetracycline (TC). The Fe 3 O 4 @COFs@MIPs, which was prepared by layer-by-layer modification method, had good magnetism and excellent adsorption ability. With the help of disposable SPE, equipped with a magnet, the electrode modification process was simplified and the detection efficiency was improved. Under optimal conditions, the fabricated electrochemical sensor exhibited linearity ranging from 1 × 10 -10 to 1 × 10 -4 g mL -1 . It had good selectivity, excellent reproducibility, desirable stability and remarkable applicability. The fabricated sensor was successfully applied to detect TC in real samples with satisfactory recoveries (96.15-106.20%). The detection strategy separated the recognition and adsorption process from the electrochemical detection process, providing a design idea for the application of COFs in the construction of high-efficiency molecularly imprinted electrochemical sensors., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Development of methods with high selectivity and sensitivity for detection of trace ribavirin (RBV) is of great importance for environmental protection and food safety. Herein, we proposed a simple yet valid strategy to construct the highly selective ratiometric fluorescence sensing platform (BA-LMOFs@MIP) for analysis of RBV based on boric acid-functionalized lanthanide metal-organic framework (BA-LMOFs) coupled with molecularly imprinted polymer (MIP). In this strategy, BA-LMOFs featured with dual-emission and pH-responsive behavior were first synthesized as supporter. Benefiting from boric acid group of BA-LMOFs, RBV was easily immobilized onto its surface, taking advantage of template immobilization-based surface imprinting means to fabricate BA-LMOFs@MIP with dual recognition sites for the first time. The synergistic effect of covalent boronate affinity-based recognition unit and non-covalent imprinting sites enabled BA-LMOFs@MIP to exhibit superior selectivity and binding efficiency to RBV. BA-LMOFs as signal tag endowed BA-LMOFs@MIP with desirable sensitivity, photostability and hydrophilicity. More importantly, BA-LMOFs@MIP-based sensor displayed a wide linear range for RBV from 25 to 1200 ng mL -1 with a detection limit down to 7.62 ng mL -1 . The sensor was finally applied to RBV determination in real samples, and the obtained results revealed that BA-LMOFs@MIP would be a promising candidate for monitoring of RBV in complex systems., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In order to solve inherent problems of traditional molecularly imprinted electrochemical sensors (MIECS), a novel platform of surface molecularly imprinted magnetic metal-organic frameworks (mMOFs@MIPs) was coupled with magneto electrode to establish magnetic MIECS for the recognition of oxytetracycline (OTC). mMOFs@MIPs were synthesized using layer-by-layer modification method for the recognition of OTC. With the help of magneto electrodes, mMOFs@MIPs can be magnetically modified on the electrode surface, forming the electrochemical sensing interface. The imprinted cavities of mMOFs@MIPs can act as the electron channel of the probe to realize label-free detection of OTC. A linear response was obtained within the OTC concentration range of 1.0 × 10 -9 g mL -1 -1.0 × 10 -4 g mL -1 . The applicability of the sensor was estimated using the spiking and recovery method in milk samples with the recoveries ranging from 89.0% to 103.1%. It has potential applications in food safety analysis with high throughput detection capability, high specificity and good stability., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

A simple, efficient and sensitive molecularly imprinted electrochemiluminescence sensor (MIECLS) based on reduced graphene oxide (rGO) and upconversion nanoparticles (UCNPs) was developed for determination of clenbuterol (CLB). In this study, rGO generated by electrodeposition of graphene oxide not only acted as carrier for immobilizing UCNPs, but also had a significant impact in boosting electrochemiluminescence (ECL) response of UCNPs thanks to its high conductivity, superior electron transport rate and large specific surface area. UCNPs as an advanced ECL emitter possessed wonderful ECL performance. Furthermore, the introduction of molecularly imprinted polymers (MIP) endowed the ECL sensor a new character of specifically identifying analyte CLB. Under the optimal experimental conditions, the ECL signal was proportional to the logarithm of CLB concentration in the range of 10nM to 100µM with a low detection limit of 6.3nM. The proposed MIECLS combining the advantages of UCNPs-ECL and MIP exhibited good sensitivity, desirable selectivity and favorable stability, indicating enormous potential in the future of food safety detection., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A novel fluorescence material with thermo-sensitive for the enrichment and sensing of protein was successfully prepared by combining molecular imprinting technology with upconversion nanoparticles (UCNPs) and metal-organic frameworks (MOFs). Herein, the UCNPs acted as signal reporter for composite materials because of its excellent fluorescence property and chemical stability. MOFs were introduced to molecularly imprinted polymer (MIP) due to its high specific surface area which increases the rate of mass transfer relative to that of traditional bulk MIP. The thermo-sensitive imprinted material which allows for swelling and shrinking with response to temperature changes was prepared by choosing Bovine hemoglobin (BHB) as the template, N-isopropyl acrylamide (NIPAAM) as the temperature-sensitive functional monomer and N,N-methylenebisacrylamide (MBA) as the cross-linker. The recognition characterizations of imprinted material-coated UCNPs/MOFs (UCNPs/MOFs/MIP) were evaluated, and the results showed that the fluorescence intensity of UCNPs/MOFs/MIP reduced gradually with the increase of BHB concentration. The fluorescence material was response to the temperature. The adsorption capacity was as much as 167.6 mg/g at 28°C and 101.2mg/g at 44°C, which was higher than that of traditional MIP. Therefore, this new fluorescence material for enrichment and sensing protein is very promising for future applications., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A novel strategy is reported for the fabrication of bis-aniline-crosslinked Au nanoparticles (NPs)-CdSe/ZnS quantum dots (QDs) array composite by facil one-step co-electropolymerization of thioaniline-functionalized AuNPs and thioaniline-functionalized CdSe/ZnS QDs onto thioaniline-functionalized Au elctrodes (AuE). Stable and enhanced cathodic electrochemiluminescence (ECL) of CdSe/ZnS QDs is observed on the modified electrode in neutral solution, suggesting promising applications in ECL sensing. An advanced ECL sensor is explored for detection of 2-methyl-4-chlorophenoxyacetic acid (MCPA) which quenches the ECL signal through electron-transfer pathway. The sensitive determination of MCPA with limit of detection (LOD) of 2.2 nmolL(-1) (S/N=3) is achieved by π-donor-acceptor interactions between MCPA and the bis-aniline bridging units. Impressively, the imprinting of molecular recognition sites into the bis-aniline-crosslinked AuNPs-CdSe/ZnS QDs array yields a functionalized electrode with an extremely sensitive response to MCPA in a linear range of 10 pmolL(-1)-50 μmolL(-1) with a LOD of 4.3 pmolL(-1 ()S/N=3). The proposed ECL sensor with high sensitivity, good selectivity, reproducibility and stability has been successfully applied for the determination of MCPA in real samples with satisfactory recoveries. In this study, ECL sensor combined the merits of QDs-ECL and molecularly imprinting technology is reported for the first time. The developed ECL sensor holds great promise for the fabrication of QDs-based ECL sensors with improved sensitivity and furthermore opens the door to wide applications of QDs-based ECL in food safety and environmental monitoring., (Copyright © 2015 Elsevier B.V. All rights reserved.)

In this work, we presented a three-dimensional (3D) molecularly imprinted electrochemical sensor (MIECS) with novel strategy for ultrasensitive and specific quantification of metolcarb based on prussian blue (PB) mediated amplification combined with signal enhancement of ordered mesoporous carbon. The molecularly imprinted polymers were synthesized by electrochemically induced redox polymerization of para aminobenzoic acid (p-ABA) in the presence of template metolcarb. Ordered mesoporous carbon material (CMK-3) was introduced to enhance the electrochemical response by improving the structure of the modified electrodes and facilitating charge transfer processes of PB which was used as an inherent electrochemical active probe. The modification process for the working electrodes of the MIECS was characterized by scanning electron microscope (SEM) and cyclic voltammetry (CV), and several important parameters controlling the performance of the MIECS were investigated and optimized in detail. The MIECS with 3D structure had the advantages of ease of preparation, high porous surface structure, speedy response, ultrasensitivity, selectivity, reliable stability, good reproducibility and repeatability. Under the optimal conditions, the MIECS offered an excellent current response for metolcarb in the linear response range of 5.0 × 10(-10)-1.0 × 10(-4) mol L(-1) and the limit of detection (LOD) was calculated to be 9.3 × 10 (-11)mol L(-1) (S/N = 3). The proposed MIECS has been successfully applied for the determination of metolcarb in real samples with satisfactory recoveries. Furthermore, the construction route of this ultrasensitive 3D MIECS may provide a guideline for the determination of non-electroactive analytes in environmental control and food safety., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template quinoxaline-2-carboxylic acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0×10(-8)-1.0×10(-4) and 1.0×10(-4)-5.0×10(-4) mol L(-1) with a low detection limit of 2.1 nmol L(-1). The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6-98.2%) and satisfactory precision (1.9-3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A novel dual-function material was synthesized by anchoring a molecularly imprinted polymer (MIP) layer on CdTe/ZnS quantum dots (QDs) using a sol-gel with surface imprinting. The material exhibited highly selective and sensitive determination of ractopamine (RAC) through spectrofluorometry and solid-phase extraction (SPE) coupled with high performance liquid chromatography (HPLC). A series of adsorption experiments revealed that the material showed high selectivity, good adsorption capacity and a fast mass transfer rate. Fluorescence from the MIP-coated QDs was more strongly quenched by RAC than that of the non-imprinted polymer, which indicated that the MIP-coated QDs acted as a fluorescence sensing material could recognize RAC. In addition, the MIP-coated QDs as a sorbent was also shown to be promising for SPE coupled with HPLC for the determination of trace RAC in feeding stuffs and pork samples. Under optimal conditions, the spectrofluorometry and SPE-HPLC methods using the MIP-coated QDs had linear ranges of 5.00×10(-10)-3.55×10(-7) and 1.50×10(-10)-8.90×10(-8) mol L(-1), respectively, with limits of detection of 1.47×10(-10) and 8.30×10(-11) mol L(-1), the relative standard deviations for six repeat experiments of RAC (2.90×10(-9) mol L(-1)) were below 2.83% and 7.11%., (Copyright © 2012 Elsevier B.V. All rights reserved.)

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]

A simple quartz crystal microbalance (QCM) sensor based on a sol-gel molecularly imprinted polymer (MIP) film as the recognition element was developed for patulin (PAT) detection. The high adsorption capacity of the proposed MIP for PAT was demonstrated by Scatchard equation analysis. Through the evaluation, based on the QCM frequency change, the developed sensor exhibited a linear concentration range of PAT from 7.5 × 10 −3 μg mL −1 to 6 × 10 −2 μg mL −1 with a lower detection limit of 3.1 × 10 −3 μg mL −1 (S/N = 3). The sensor showed good selective affinity for PAT (selectivity coefficient = 3.82) as well as good reproducibility and long-term stability. The developed sensor was tested on its ability to detect PAT in real samples through a spiking and recovery study with the recoveries ranging from 76.9% to 91.3% (RSDs < 8.4%). The good agreement results of the established MIP-QCM sensor and HPLC–MS method indicated that the developed method could accurately detect PAT in practical food samples. [ABSTRACT FROM AUTHOR]

Citrinin (CIT) is difficult to measure since only trace levels are present in commercial food products. In this study, a novel three-dimensional (3D) molecularly imprinted quartz crystal microbalance (QCM) sensor for trace CIT detection was constructed by electro-polymerizing o -aminothiophenol on Au nanoparticles@mesoporous carbon CMK-3 (AuNPs@CMK-3) functional composite modified Au electrode surface. Herein, AuNPs@CMK-3 functional composite acted as signal amplifier since the 3D structure and large specific surface area of AuNPs@CMK-3 functional composite were beneficial to increase the amount of effective imprinted sites and subsequently improve the sensitivity of the sensor. The preparation process of the QCM sensor was characterized by scanning electron microscope, transmission electron microscope, cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimal conditions, the proposed sensor showed a linear frequency shift to the concentration of target CIT ranging from 6.0 × 10 −9 to 2.0 × 10 −7 mol L −1 with a low detection limit of 1.8 × 10 −9 mol L −1 (S/N = 3). The sensitive sensor exhibited excellent selective recognition, anti-interference capability, reproducibility and long-term stability, and was successfully applied to analyze trace CIT in cereal samples with satisfactory recoveries, suggesting the proposed sensor is promising for the detection of CIT at trace levels in foods. [ABSTRACT FROM AUTHOR]

A molecularly imprinted polymer (MIP) based microfiber differential demodulation sensing system for sodium benzoate (SB) concentration detection is proposed. The specific binding of MIP on the surface of microfibers with SB can lead to changes in local refractive index (RI). RI change induces a drift in the interference wavelength, which can be monitored by the power difference between two fiber Bragg gratings (FBGs). The sensing system can detect SB in the concentration range of 0.1–50 μg/ml, and interference wavelength and FBG power difference sensitivities are 0.55 nm/(μg/ml) and 2.64 dB/(μg/ml) in the low concentration range of 0.1–1 μg/ml, respectively, with a limit of detection (LOD) of 0.1 μg/ml. This microfiber differential demodulation sensing system is not only simple to fabricate, but also simplifies the demodulation equipment to reduce the cost, which providing a simple, reliable and low-cost technique for the quantitative detection of SB concentration in beverages and flavoured foods. • Differential demodulation system combined with molecular imprinting technique. • The sodium benzoate detection range is 0.1–50 μg/ml and detection limit is 0.1 μg/ml. • The sensing system is simple to fabricate, high sensitivity, good stability. • This differential sensing system has a broad prospect in the field of food safety. [ABSTRACT FROM AUTHOR]

A novel molecularly imprinted electrochemical sensor was successfully fabricated for detection of amantadine (AM) residue in animal-derived foods. This molecularly imprinted film was prepared by electrodepositing o -aminothiophenol ( o -AT) on a gold electrode surface by cyclic voltammetry (CV). A series of parameters, including template/monomer ratio, CV scanning cycle number, and immersion time, were optimized in detail for controlling the performance of this imprinted sensor. The fabricated sensor exhibited remarkable characteristics of high selectivity, sensitivity, and reproducibility, and long-term stability for AM detection. The imprinting factor for AM achieved to 2.33 and the selectivity factor for three structural analogues achieved to 6.20, 5.29 and 3.95. Under optimal experimental conditions, good linearity was observed between the current response and AM concentration, ranging from 4.0 × 10 −7 mmol L −1 to 8.0 × 10 −6 mmol L −1 , with a detection limit of 3.06 × 10 −9 mmol L −1 ( S / N = 3). Satisfactory results for the measurement of real samples were also obtained using the proposed sensor, and were consistent with those derived from typical high-performance liquid chromatography-tandem mass spectrometry with a high correlation coefficient (R 2 > 0.99). These results demonstrate that the proposed sensor could serve as a valuable tool for accurate and reliable detection of AM residue in animal-derived foods. [ABSTRACT FROM AUTHOR]