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Ideal binding ligands for anchoring proteins are essential for the design and assembly of desirable molecularly imprinted polymers (MIPs). In this study, bovine serum albumin-MIPs (BSA-MIPs) were successfully prepared by orchestrating the involvement of orientation-controllable binding ligands via sequential thiol-ene click and thiol-ene-amine conjugation. We showed that the optimal thiol-ene-amine conjugates and binding ligands were decisive in determining the rebinding capacity and selectivity. The pyrrolidinyl MIPs exhibited the best adsorption capacity of 352 ± 22 mg/g and a superior imprinting factor of 4.72 among MIPs with various binding ligands. These favourable results were further studied by computational simulation and isothermal titration calorimetry (ITC). Molecular docking revealed the preferential binding free energy and H-bonds between BSA residues and the thiol-ene-amine conjugates. Meanwhile, the pyrrolidinyl ligand motif enabled entropy-favourable affinity to be achieved via hydrophobic effects with the BSA template by ITC thermodynamics. Because of these favourable bindings, the MIPs exhibited excellent adsorption specificity to BSA over competing proteins. The proof-of-concept of MIPs with orientation-controllable conjugates and proven binding ligands for target proteins demonstrates that this material is promising for use with a real biological sample.

Pharmaceuticals are vital components of our daily life; however, as micropollutants, they also pose a significant wastewater treatment challenge. As the complete avoidance of pharmaceuticals is not a desired or viable solution, a targeted wastewater treatment must be implemented. Molecularly imprinted polymers can remove these contaminants from wastewater; however, determining their optimal constituents is a costly and lengthy experimental process. Here, we present a computational protocol used to design imprinted polymers for the targeted removal of fluoxetine, leveraging rigorous molecular models and simulation methods to study the crucial complexation step during the pre-polymerisation mixtures. Our molecular dynamics results validated with available experimental measurements correlate calculated radial distribution functions and predicted hydrogen bonding with experimental imprinting factors for various functional monomers. The simulated results are also analysed via Kirkwood-Buff integrals for the study of the role of funtional monomers in the whole pre-polymerization mixture. Marked dependencies of the functional monomer’s carbonyl, hydroxyl and esters interactions are described, and functional monomer selection criteria using hydrogen bonding time and KBI initial slope and limiting value are proposed. This analysis offers further insights into why itaconic acid, amongst methacrylic acid, 2 (hydroxyethyl)methacrylate, acrylamide and acrylonitrile, is the optimal monomer for imprinting fluoxetine when ethylene glycol dimethacrylate is used as crosslinker and dimethylsulfoxide as solvent. Our computational protocol compiles off-the-shelf open-source software with well-established simulation methodologies to offer a viable alternative to the resource and time-consuming experimental task of choosing the best functional monomer for a given target molecule.

Misusing or overusing antibiotics in livestock and poultry can result in the accumulation of mentioned drugs in the animal meat. Consequently, its consumption by humans and therefore increasing the risks of antibiotic resistance emergences. In order to decrease these risks, constant monitoring of the meat samples is necessary. Therefore, the concentration of antibiotics needs to be lower than maximum residue limits. As meat is a complex matrix, sample preparation is a mandatory step in the analysis. Molecularly imprinted polymers are one of the extensively studied tools in this aspect. These polymers exhibited great affinity and selectivity towards the target compound/s. In this work, a collection of studies from 2017 to 2021 is reviewed. Inclusion criteria were formed around papers incorporating molecularly imprinted polymers as a means of extraction or detection of antibiotics in meat samples. This review represents different synthesis methods of these polymers and their applications in the extraction and determination of antibiotics from meat samples. It also demonstrates the advantages, gaps and weakness of these systems in the food chemistry field. It can also act as a guide for the design and development of novel polymer-based analytical methods for food applications. Throughout this review, the methods for determination of antibiotic residues in food samples using conventional and novel MIP based techniques are discussed, by coupling MIPs with other analytical techniques, Limit of detection and quantification and recovery rates will improve significantly, which results in designing of platforms in food chemistry analysis with higher efficacy.

Molecularly imprinted polymers (MIPs) having the potential to mimic the selectivity and sensitivity of biological molecular recognition are blended here with piezoelectric transducer (EQCM) able to provide ‘real time’ monitoring of molecular level events with extreme sensitivity. In this work, molecularly imprinted polymer nanoparticles selective for a psychoactive drug, cathinone were synthesized, characterized and applied for specific and selective uptake in water. Nanoparticles were separated by centrifugation and characterized for their size and zeta potential. p-Phenylene diamine was chosen as functional monomer to imprint S-cathinone via in silico studies. Molecularly imprinted nanoparticles were eletrodeposited on gold coated quartz crystal electrode of electrochemical quartz crystal microbalance (EQCM). Molecular imprinting experiments were optimized for selective and specific uptake of S-cathinone. Thus fabricated EQCM sensor was able to discriminate between stereoisomers and other close structural analogues also. Imprinting data were successfully fitted to Freundlich adsorption isotherm and curves for non-imprinted and imprinted data were compared. Under optimized conditions, response of nanoMIP-EQCM sensor is linearly proportional to S-cathinone concentration with detection limit as 0.12 ng mL−1 and quantification limit as 0.409 ng mL−1 and imprinting factor as 8. Hence, a highly specific and selective nanoMIP-EQCM sensor is fabricated in a facile manner.

Formalin is extensively used by traders to preserve various food items like fish and mushrooms, but it has serious health hazards. Detection of formalin content in foods is a challenging problem and in the proposed work, an electrochemical sensor based on a molecular imprinted polymer of acrylonitrile over graphite platform (MiPAN@GP electrode) is pioneered for the recognition of formalin (FAL). The synthesized MiPAN@GP electrode material was characterized with Fourier transform infra-red (FTIR) spectroscope, UV-visible (UV-vis) spectroscope, and scanning electron microscope (SEM). The analytical performance of the electrode was evaluated by a three electrode system using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). A wide linear range from 10 μM to 1000 μM with a limit of detection of 0.63 μM was obtained. The MiPAN@GP sensor exhibited various advantages, such as low cost, high repeatability, high reproducibility, long term stability, and good selectivity. The practical applicability of the MiPAN@GP electrode was tested with mushroom and fish extracts which yielded satisfactory results and high accuracy (≈ 99%) when compared with the high performance liquid chromatography (HPLC) analysis results.

In the present work, reusable magnetic molecularly imprinted polymers have been used for the first time as an adsorbent for the determination of chlorferon. Magnetic molecularly imprinted polymers have been used for the selective separation of chlorferon from the solution and sensitive fluorimetric determination has been performed using the native fluorescence of chlorferon. The developed method is rapid and determination of chlorferon was completed in an hour. Limit of detection (LOD) of the method was found to be 0.0027 mu M and the linearity of the calibration graph was observed within the range of 0.01-0.36 mu M (2.5 - 75 mu g L-1). Adsorption isotherms point out the multilayer adsorption and the heterogeneous distribution of binding sites for imprinted polymer and homogeneous binding site for non-imprinted polymer. The adsorption capacities of imprinted polymer and non-imprinted polymer were calculated as 2.03 mu mol g(-1) and 0.96 mu mol g(-1), respectively and the imprinting factor was found to be 2.11. The interference effects of some organic compounds and characterization studies were also evaluated. The method has been applied to honey and tap water samples and the recoveries were found to be in the range of 91.3 and 101.1 %., 18-EGEMATAL-003, 18-EGEMATAL-003.

The current study utilizes molecularly imprinted polymer (MIP) technology to fabricate a cost-effective and reproducible electrode for selective determination and quantitative prediction of epicatechin (EC) in green tea. Acrylamide (AAm) co-polymerized with ethylene glycol dimethacrylate (EGDMA) and optically inactive quercetin (Q) as the template has been used to make the MIP-Q@G material. The voltammetric experiment has been performed using the MIP-Q@G electrode with the help of a three-electrode configuration. In addition to a low detection limit (LoD) of 0.33 μM, the electrode exhibited two wide ranges of linearity from 1 μM – 100 μM and 100 μM to 500 μM. The limit of quantitation (LoQ) of the electrode was found to be 1.09 μM. Partial least square regression (PLSR) and principal component regression (PCR) models have been developed to investigate the predictive ability of the MIP-Q@G electrode using the differential pulse voltammetry (DPV) signals and the high- performance liquid chromatography (HPLC) data. Both PLSR and PCR models achieved prediction accuracies of 94.54 % and 94.41% with a root mean square error of calibration (RMSEC) of 0.113 and 0.119, respectively.

Inspired by the easy intercalation of quinoxaline heterocyclic aromatic amines (HAAs) in double-stranded DNA (dsDNA), we synthesized a nucleobase-functionalized molecularly imprinted polymer (MIP) as the recognition unit of an impedimetric chemosensor for the selective determination of a 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (7,8-DiMeIQx) HAA. HAAs are generated in meat and fish processed at high temperatures. They are considered to be potent hazardous carcinogens. The MIP film was prepared by potentiodynamic electropolymerization of a pre-polymerization complex of two adenine- and one thymine-substituted bis(2,2′-bithien-5-yl)methane functional monomer molecules with one 7,8-DiMeIQx template molecule, in the presence of the 2,4,5,2′,4′,5′-hexa(thiophene-2-yl)-3,3′-bithiophene cross-linking monomer, in solution. The as-formed MIP chemosensor allowed for the selective impedimetric determination of 7,8-DiMeIQx in the 47 to 400 μM linear dynamic concentration range with a limit of detection of 15.5 μM. The chemosensor was successfully applied for 7,8-DiMeIQx determination in the pork meat extract as a proof of concept.

In this study, Poly(methacrylic acid-co-diallyldimethylammonium chloride) or Poly(MAA-PDDA) was synthesized as a cationic molecularly imprinted nano-polymer. After in vitro assays such as cytotoxic...

Herein, a strategy for a metal ion-imprinted artificial antibody with recognition sites tagged by fluorescein was carried out to construct the selective sites with a sensitive optical response signal to the specific metal ion. The synthesized silica nanoparticles were modified by the derivative residue group of 3-aminopropyltriethoxysilane conjugated with a 4-chloro-7-nitro-1,2,3-benzoxadiazole (NBD-Cl) molecule through the hydrolysis and condensation reactions. The as-prepared silica nanoparticles were encapsulated by metal ion (Cu2+, Cd2+, Hg2+, and Pb2+)-imprinted polymers with nanostructured layers through the copolymerization of ethyl glycol dimethyl methacrylate (EGDMA) as a cross-linker, AIBN as an initiator, metal ions as template molecules, AA as a functional monomer, and acetonitrile as a solvent. The layers of molecular imprinted polymers (MIPs) with a core-shell structure removed template molecules by EDTA-2Na to retain the cavities and spatial sizes to match the imprinted metal ions. The microsensor arrays were achieved by the self-assembly technique of SiO2@MIP nanoparticles on the etched silicon wafer with regular dot arrays. The nanostructured-shell layers with fluorescence-tagged recognition sites rebound metal ions by the driving force of concentration difference demonstrates the high selective recognition and sensitive detection to heavy metal ions through the decline of fluorescence intensity. The LOD concentration for four metal ions is down to 10-9 mol·L-1. The method will provide biomimetic synthesis, analyte screen, and detection of highly dangerous materials in the environment for theoretical foundation and technological support.

Quantitative analysis of catecholamines and their acidic metabolites can provide vital information for diagnosis and treatment of various diseases (such as adrenal tumors). However, complicated purification protocols are usually required to isolate the analytes. Molecularly imprinted polymers (MIPs) have attracted considerable attention as a method of selectively separating desired compounds from their matrix. Therefore, we propose a synthetic procedure for new molecularly imprinted sorbents that possess selective binding sites for both catecholamines and their acidic metabolites. The new polymer utilizes non-covalent and semi-covalent imprinting methods. The binding properties of MIPs were evaluated using chromatographic experiments. The results suggest that the MIPs bind with catecholamines much more selectively than with their acidic metabolites. Therefore, increasing sorption selectivity of the acids would make it possible to perform simultaneous extraction of both compound groups.

Chiral resolution of binaphthylamine is often a toilful conundrum in the field of analytical chemistry and biomedicine. The work puts forward a selective, sensitive, and miniaturized analytical method based on molecularly imprinted polymers (MIPs) as adsorbent for miniaturized tip solid-phase extraction (MTSPE) in the separation of binaphthylamine enantiomer. This method combines the advantages of MIPs (high selectivity), MTSPE (low consumption), and high-performance liquid chromatography (HPLC, high sensitivity). A simple synthesis methodology of MIP (P2) was conducted through bulk polymerization with (S)-(-)-1,1'-binaphthyl-2,2'-diamine (S-DABN) as template together with methacrylic acid monomer, and ethylene glycol dimethacrylate as cross-linker in proper porogen, realizing a selective recognition and efficient enrichment for S-DABN. The method exhibited appreciable linearity (0.06-1.00 mg ml-1 ), low quantification limit (0.056 mg ml-1 ), good absolute recoveries (45.70%-69.29%), and high precision (relative standard deviations ≤ 3.54%), along with low consumption (0.50 ml sample solution and 25.0 mg adsorbent). Based on the density functional theory, computational simulation was used to make a preliminary prediction for rational design of MIPs and gave a reasonable elaboration involving the potential mechanism of templates interacting with functional monomers. The adsorption kinetics and thermodynamics were investigated to evaluate the recombination process of substrates. In addition, the selectivity of MIPs for S-DABN was obtained by MIP-MTSPE coupled with HPLC, which supports the feasibility of this convenient design process. The proposed method was employed for selective extraction of S-DABN and exhibited promising potential in the application of chiral analysis.

A straightforward in situ detection method for dengue infection was demonstrated through the molecular imprinting of a dengue nonstructural protein 1 (NS1) epitope into an electropolymerized molecularly imprinted polyterthiophene (E-MIP) film sensor. The key enabling step in the sensor fabrication is based on an epitope imprinting strategy, in which short peptide sequences derived from the original target molecules were employed as the main template for detection and analysis. The formation of the E-MIP sensor films was facilitated using cyclic voltammetry (CV) and monitored in situ by electrochemical quartz crystal microbalance (EC-QCM). Surface properties were analyzed using different techniques including atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and polarization modulation-infrared reflection-adsorption (PM-IRRAS). The standard calibration curve (R = 0.9830) was generated for the detection of the epitope, Ac-VHTWTEQYKFQ-NH2, with a linear range of 0.2 to 30 μg/mL and detection limit of 0.073 μg/mL. A separate calibration curve (R = 0.9786) was obtained using spiked buffered solutions of dengue NS1 protein, which resulted in a linear range of 0.2 to 10 μg/mL and a detection limit of 0.056 μg/mL. The fabricated E-MIP sensor exhibited long-term stability, high sensitivity, and good selectivity towards the targeted molecules. These results indicated that the formation of the exact and stable cavity imprints in terms of size, shape, and functionalities was successful. In our future work, we aim to use our E-MIP sensors for NS1 detection in real-life samples such as serum and blood.

Tetrabromobisphenol A (TBBPA) has been considered as one of the persistent organic pollutants in water. It is urgent to determine TBBPA in environment due to its detriment to humans and aquatic species. However, sample pretreatment prior to instrumental analysis is always required because of the low concentration of TBBPA and the complexity of the matrix. A novel molecularly imprinted polymer (MIP) was prepared using magnetic mesoporous TiO2 as matrix. The mesoporous TiO2 layer could provide sufficient recognition sites for MIP, and Fe3O4 core can facilitate its separations from liquid medium. After azido was introduced onto Fe3O4@mTiO2 by non-covalent effect, alkynyl-terminated reversible addition − fragmentation chain transfer (RAFT) agent was fixed by click chemistry. The MIP was prepared via RAFT polymerization in the presence of TBBPA using 4-vinylpyridine (4-VP) and ethyleneglycol dimethacrylate (EGDMA) as functional monomer and crosslinker, respectively. The adsorption process reached equilibrium within 20 min. The maximum adsorption capacity of MIP for TBBPA at an ideal ratio of 4-VP and EGDMA was 41.67 mg g−1 and was much higher than that of non-imprinted polymer (20.92 mg g−1). The MIP also exhibits excellent affinity towards TBBPA in the presence of structural analogs. Additionally, the as-prepared MIP can be repeatedly reused due to the magnetic core.

Using biocompatible polymer nanofibrous conduits with a controlled drug delivery have attracted much attention for peripheral nerve regeneration. This work was aimed at preparing electrospun poly ( l -lactide-co- D , l -lactide) (PLDLLA) containing multi-walled carbon nanotubes (MWCNTs) and 4-aminopyridine (4-AP)-loaded molecularly imprinted nanoparticles (MIP4-AP) as well as evaluating their performance in in vitro and in vivo assessments. After synthesis of MIP4-AP based on poly (methacrylic acid) with imprinting factor of 1.78, it was incorporated into the PLDLLA/MWCNTs nanofibers to optimize. By adjusting the process variables, the average diameter and electrical conductivity of the nanofibrous sample were 92 nm and 2870 × 10−7 S cm−1, respectively. Afterward, 4-AP release of the optimum sample showed the presence of MIP4-AP leading to initial burst release decrease and plateau level postpone up to 96 h. Moreover, the culture results of PC12 as neuroblastoma cell line on optimal PLDLLA/MWCNTs/MIP4-AP nanofibrous sample revealed the highest cell proliferation without cytotoxicity compared to neat nanofibers. Eventually, the animal model experiment exhibited that the conductive conduit based on the optimum sample was able to repair the rat's sciatic nerve after four weeks in accordance with sciatic function index and histological studies.

hER-MIP is a molecularly imprinted polymer (MIP) that has been shown to selectively collect human estrogen receptor (hER) binding active substances. However, environmental samples contain various chemicals depending on the location and regional differences, and the hER binding activity depends on the sample type. Thus, the general applicability of hER-MIP to actual environmental samples must be elucidated. In this study, 48 environmental samples were collected and screened with hER-MIP, and a yeast assay was performed to evaluate the adsorption characteristics of the samples according to the adsorption and elution fractions. The results showed that hER-MIP collects hER binding active substances almost selectively but does not collect constitutive androstane receptor (CAR) binding active substances selectively. CAR binding activity was detected in the adsorbed fraction because several hER binding active substances also demonstrate CAR binding activity.

Background: Improper use of antibiotics and their discharge into the environment have serious and dangerous consequences. About 30-30% of antibiotics are not metabolized in the body and enter the environment through urine and feces, so the main source of antibiotics in the environment is wastewater treatment plant effluent. The aim of this study was to investigate the removal efficiency of ciprofloxacin (CIP) from aqueous media by molecularly imprinted polymer (MIP). Methods: This study is an experimental-laboratory study performed in a reactor with a discontinuous system. In this study, the effect of parameters such as solution pH, adsorbent dose, initial concentration of CIP, reaction contact time and reaction temperature on the reduction rate the antibiotics amoxicillin and CIP were administered. Results: Results showed that removal efficiency for both antibiotics was increased with increasing contact time and adsorbent mass and initial antibiotics concentration while decreased with increasing solution pH and the best pH to remove was neutral pH. Equilibrium data were analyzed by Freundlich and Langmuir isotherm models and the results showed that the data from Langmuir isotherm had a higher correlation coefficient. In addition, the reaction rate was performed with pseudo-first-order and pseudo-second-order models, and the data were consistent with pseudo second order kinetic kinetics. According to result of thermodynamic study, entropy changes (ΔSO), enthalpy changes (ΔHO) and Gibbs free energy (ΔGO) were negative that represent the adsorption process is spontaneous and exothermic. Conclusion: The results of this study showed that the process of adsorption of MIP is a very effective process for removing the CIP from aqueous solutions.

In this research project, a selective and sensitive sensor was electrochemically designed to measure metformin hydrochloride (MET) based on molecularly imprinted polymer (MIP). To prepare the sensor, the polypyrrole was electrochemically synthesized on a pencil graphite electrode (PGE), which modified with silver nanoparticles (AgNPs). Cyclic voltammetry and differential pulse voltammetry techniques were performed to fabricate the sensor and quantitative measurements, respectively. To select the functional monomers, a computational method was used. Some critical factors controlling the performance of the MIP–AgNPs–PGE were optimized using Plackett–Burman design and central composite design methods. Under optimal conditions, a calibration curve was obtained in the range 0.1–1000 µM with a limit of detection of 6.8 nM (S/N = 3, n = 3) and limit of quantitation of 22.8 nM (S/N = 10, n = 3). RSD of 3.9 and 4.1% were obtained for repeatability and reproducibility of the system, respectively. Furthermore, the modified sensor was successfully used for the determination of MET concentration in some real samples.

Zearalenone is a fungal contaminant that is widely present in grains. Here, a novel molecularly imprinted membrane based on SOM-ZIF-8 was developed for the rapid and highly selective identification of zearalenone in grain samples. The molecularly imprinted membrane was prepared using polyvinylidene fluoride, cyclododecyl 2,4-dihydroxybenzoate as a template and SOM-ZIF-8 as a carrier. The factors influencing the extraction of zearalenone using this membrane, including the solution pH, extraction time, elution solvent, elution time and elution volume were studied in detail. The optimized conditions were 5 mL of sample solution at pH 6, extraction time of 45 min, 4 mL of acetonitrile:methanol=9:1 as elution solvent, and elution time of 20 min. This method displayed a good linear range of 12∼120 ng·g-1 (R2 =0.998) with the limits of detection and quantification of this method are 1.7 ng·g-1 and 5.5 ng·g-1 , respectively. In addition, the membrane was used to selectively identify zearalenone in grain samples with percent recoveries ranging from 87.9% to 101.0% and relative standard deviation of less than 6.6 %. Overall, this study presents a simple and effective chromatographic pretreatment method for detecting zearalenone in food samples. This article is protected by copyright. All rights reserved.

Aiming at enhancing the detection efficiency and identification accuracy of tetracycline under a high-temperature condition, this study focuses on an innovative fluorescent sensing system (MIP@CQD-PCM) based on molecularly imprinted phase-change microcapsules along with the carbon quantum dots (CQDs) embedded in their shell. This system was fabricated by microencapsulating n-eicosane as a phase change material (PCM) core within a CQDs-embedded SiO2 shell, followed by coating a tetracycline-templated molecularly imprinted polymer (MIP) layer onto the surface of the SiO2 shell. The specific recognition sites to tetracycline molecules were finally achieved by removal of tetracycline template from the MIP layer. Comprehensive characterizations and investigations on the structure and performance of the fluorescent sensing system were given to confirm its successful fabrication in accordance to our design strategy. The resultant MIP@CQD-PCM exhibits a satisfactory thermal storage capacity and phase-change cycle stability for temperature regulation and thermal management applications under a phase-change enthalpy of over 162 J/g. Most of all, a typical fluorescence-quenching effect was obtained from the combination of the CQDs embedded in the SiO2 shell and the tetracycline molecules adsorbed in the MIP layer. This makes the MIP@CQD-PCM achieve an enhanced capability for the fluorescence identification of tetracycline in a high-temperature environment through the in situ thermal management of its PCM core. The MIP@CQD-PCM also displays high selectivity and good reusability for tetracycline detection in industrial applications. This work provides a promising strategy for the design and development of fluorescent sensing systems with high recognition efficiency and identification accuracy in the detection of hazardous substances.

The molecularly imprinted polymers (MIPs) prepared from a single template theoretically only have selectivity for the template molecule itself, which limits its application. Dual/multi-template molecularly imprinted polymers (D/MMIPs) not only have the selectivity toward template but also increase the throughput of separation analysis and the range of applications in actual samples. In this review, application progresses of multi/dual-imprinting technology in pharmaceutical analysis, environmental pollutant analysis, biological macromolecule analysis, extraction of active ingredient from natural product, catalysis, transport agent, denitrifying and desulfurizing agent, molecular and ion analysis are discussed. These progresses will advance the further development of molecularly imprinting technology, and D/MMIPs will be used in more fields.

Background Pesticide residues due to overuse and abuse in foods and relevant matrices have posed a serious threat to public health in the world. Highly selective and sensitive detection of diverse pesticides is of great urgency and importance in food safety control. Scope and approach Molecular imprinted polymer (MIP)-based optical sensors with MIPs as recognition elements have become the fascinating candidates for pesticide monitoring in various real samples due to its excellent stability, reusability and low production cost. And the high-quality publications on MIP-based optical sensors for pesticide detection have grown exponentially. In this review, we first discuss the current state-of-the-art of synthesis approaches and application of MIPs. Then, we give a comprehensive overview on the recent advances of the emerging MIP-based optical sensors for pesticide detection in food systems over the past five years, with a particular emphasis on fluorescent, colorimetric, chemiluminescent, electrochemiluminescent, surface plasmon resonance and surface-enhanced Raman spectroscopy sensors. Beyond a highlight of the real-world application and advantages of these proposed sensors, we also address their current challenges and future trends, as well as the ongoing efforts and strategies for developing novel highly-effective MIP-based optical sensing platforms. Key findings and conclusions This review will open up new horizons regarding MIP-based optical sensors for wide application in food safety.

Stress nowadays is one of the major causes of various pathologies in humans. Monitoring of stress associated biomarker levels in biological fluids on demand can help in effective management of stress. Since cortisol has been recognised as a potential biomarker for stress, its detection can help in an appropriate therapeutic intervention or stress management. Various types of biosensors such as immunosensors, aptasensors, molecularly imprinted polymers and enzyme-linked based biosensors have been reported till now for the cortisol sensing. Out of all, aptasensors have shown various advantages over other sensors such as specificity, high room temperature stability, reproducibility, etc. Among various reported aptasensors, full-length aptamer (> 60-mer) has been used. However, only a portion of aptamer interact with its target, therefore, establishing its structure–activity relationship is vital for a biosensor to achieve an optimized performance. In the current work, we have rationally truncated already existing 61-mer aptamer sequence into its smaller variant with only 14 bases. Parent and truncated aptamers were immobilized on the graphene quantum dots modified electrodes for electrochemical biosensing of cortisol. Detection limits and cross-reactivities of both the aptamers were compared and it was found that truncated aptamer showed better results in terms of specificity. Though the limit of detection is same for both parent and truncated aptamers, i.e. 0.1 pg/ml but cross-reactivity from various structural analogues in sensing is reduced drastically in case of truncated variant. In brief, we are reporting a label-free electrochemical aptasensor utilizing the truncated aptamer (14-mer) that has remarkable limit of detection (0.1 pg/ml), high level of selectivity and reproducibility for the direct analysis of the cortisol.

Contamination and carry-over of trace zearalenone (ZON) and its metabolite α-zearalanol (α-ZOL) from different feedstuffs to foods in different seasons were monitored by molecularly imprinted solid-phase extraction (MISPE) and high-performance liquid chromatography with fluorescence detector (HPLC-FLD) for the first time. Molecularly imprinted polymers (MIPs) bond ZON and α-ZOL selectively were prepared using cyclododecanyl-2,4-dihydroxybenzoate (CDHB) as the pseudo template. By using MIPs as sorbents of MISPE, selective enrichment of ZON and α-ZOL by MISPE increased the accuracy of HPLC-FLD. Seasonal differences on ZON contamination were observed in different feedstuffs and raw milk. But only the carry-over of ZON from cow feedstuffs to raw milk was observed. No α-ZOL contamination was detected. The humid and warm weather in April and July in Wuhan increased ZON contamination levels and the risk of ZON transmission from cow feedstuffs to milk. Seasonal differences on ZON contamination and carry-over indicate the necessity of seasonal-dependent mycotoxin monitoring and safety evaluation.

An improved and alternative method for the metal-free synthesis of 5,7-dimethylcyclopentenon[2,3- c]coumarin as a possible useful aflatoxin template in the production of molecular imprinting polymers with affinity toward natural aflatoxin molecules is reported. A synthesis of 5,7-dimethylcyclopentenon[2,3- c]coumarin from 3,5-dimethoxyphenol via a Pechmann condensation involved five steps and represents an alternative commercially viable approach over existing synthetic protocols in the literature. Operational simplicity, inexpensive key raw materials, short reaction times, and excellent yields are remarkable features of this approach. The aflatoxin template was provided in 55%–67% overall yield from 3,5-dimethoxyphenol with >99% purity, evaluated by high-performance liquid chromatography, 1H NMR, 13C NMR, high-resolution mass spectrometry, and liquid chromatography–mass spectrometry.

A water-compatible molecularly imprinted polymer (MIP) was prepared for specific extraction of HIV-1 integrase inhibitor elvitegravir (EVG). It was prepared by a non-covalent free radical polymerization process using methacrylic acid as a monomer and elvitegravir as a template molecule. The MIP based solid phase extraction (MIP−SPE) cartridge was constructed for specific extraction of EVG from rat plasma samples. The effect of porogenic solvents, cross linker, pH and monomer to template ratio were studied. The developed HPLC method was validated as per ICH guidelines. The recovery of EVG using MIP−SPE technique was 98%. The LOD and LOQ of EVG were 0.01 and 0.05 µg/mL, respectively. The established method may not only be used to determine EVG but also to study the pharmacokinetics in rat plasma samples.

Graphene quantum dots (GQDs) have been widely investigated in recent years due to their outstanding physicochemical properties. Their remarkable characteristics allied to their capability of being easily synthesized and combined with other materials have allowed their use as electrochemical sensing platforms. In this work, we survey recent applications of GQDs-based nanocomposites in electrochemical sensors and biosensors. Firstly, the main characteristics and synthesis methods of GQDs are addressed. Next, the strategies generally used to obtain the GQDs nanocomposites are discussed. Emphasis is given on the applications of GQDs combined with distinct 0D, 1D, 2D nanomaterials, metal-organic frameworks (MOFs), molecularly imprinted polymers (MIPs), ionic liquids, as well as other types of materials, in varied electrochemical sensors and biosensors for detecting analytes of environmental, medical, and agricultural interest. We also discuss the current trends and challenges towards real applications of GQDs in electrochemical sensors.

Soft lithographically patterned molecularly imprinted polymers (MIP) offer highly durable, low-cost fabricated biochemical sensors, with a highly selective biorecognition mechanism. In MIP architecture, nanocavity binding sites are imprinted onto a polymer thin film coated over an interdigitated electrode structure. As the target molecules affixed to the binding sites, the frequency-dependent electroimpedance is measured across the interdigitated electrode, and the response signal is analyzed to determine analyte concentration. This letter uses poly(vinyl alcohol), N-methyl-4 (4′-formylstyryl)pyridinium methosulfate acetal (PVA-SbQ) to create the desired MIP thin film structure for detecting specific physiologically relevant small molecules, 8-isoprostane, and an oxidative stress biomarker clinical tested in blood or saliva samples. The sensor devices were rigorously tested against comparable biomolecules, including cortisol, cortisone, and progesterone, demonstrating very minimal cross sensitivity, mostly at very high concentrations and well above their physiological concentration range in exhaled breath condensate. The detectable range of 8-isoprostane in aerosolized test and control samples mimicking exhaled breath condensate was identified as 1–100 pg/mL, which comfortably covers the reported physiological concentration range (10–100 pg/mL) of this biomarker in exhaled breath.

Solid-phase extraction based on molecularly imprinted polymer is developed for rapid, simple and selective preconcentration/determination of Ni(II) from aqueous solutions. Ni(II) dimethylglyoxime (DMG/Ni(II)) complex was synthesized and polymerized with cross-linker (divinyl benzene) to obtain ion imprinted polymer [poly(DVB-DMG/Ni(II))] of Ni(II). Ni(II)IIP was prepared by precipitation polymerization using dimethylglyoxime as ligand, Ni(II) as a metal ion, methacrylic acid as a functional monomer, divinyl benzene as a crosslinking agent and 2,2'-azobisisobutyronitrile as an initiator. The mixture was polymerized thermally, after polymerization, the metal was leached with a washing solvent. Blank polymer was synthesized under the same condition but in the absence of ligand and metal ion. Optimization of crosslinker, monomer and amount of Ni(DMG) was done and it was found that the optimized value for crosslinker is 0.30 mmol, monomer 3 mmol and Ni(DMG) is 8 mL. The polymer exhibited 99.98% adsorption in the presence of Zn(II), 72.50% in the presence of Mg(II), Ca(II) and Cu(II) and 73.48% in the presence of Co(II), and less than 70% adsorption was observed in the presence of Fe(II) and Cd(II). The maximum binding of Ni(II) was obtained with [poly(DVB-DMG/Ni(II))] after optimizing the amount of crosslinker, monomer and Ni(II) DMG complex for its synthesis, and the experimental parameters like effect of pH, polymer quantity, temperature and contact time during adsorption experiments. Poly(DVB-DMG/Ni(II)) microbeads were used three times without significant loss in adsorption capacity. Determination of Ni(II) in real water samples showed that the interfering matrix had been removed during preconcentration of Ni(II) from real samples on poly(DVB-DMG/Ni(II)).

This study presents a newly developed selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) for simultaneous removal and clean up of nitenpyram (NIT) and imidaclo...

The purpose of this manuscript is to develop sustained release molecularly imprinted voriconazole (VOR) that were loaded into collagen shield (CS) for ocular treatment of fungal keratitis. Various molecularly imprinted polymer (MIP) formulae were prepared by a precipitation polymerization technique. Different monomers and crosslinkers were tested to obtain better binding capacity. Two promising formulae; (F1: VOR: Acrylamide: ethylene glycol dimethacrylate (EGDMA): benzoyl peroxide (BPO) in the molar ratio of 1:5:15:1.6 mM, respectively) and (F3: VOR: Acrylamide: methyl methacrylic acid (MMA): EGDMA: BPO in the molar ratio 1:2.5:2.5:15:1.6 mM, respectively) were selected according to their binding capacities (82.79% ± 0.86, and 94.90% ± 1.25 respectively), and their release profiles over 48 h in simulated tears fluid (STF) (41.64 ± 1.92, and 85.39 ± 1.64 respectively). Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) were carried out. The selected CS (F1 CS and F3 CS) showed sustained release profiles (57.38%± 0.72, and 98.51%±0.49 respectively) over 72 h in STF. Results of trans-corneal permeation and antifungal activity were enhanced for the optimized formula (F3 CS) compared to (F1 CS) and drug solution. Furthermore, in vivo pharmacokinetic studies were conducted showing significant increase in Cmax, delayed Tmax and promoted relative bioavailability. After ocular insertion of F3 CS in male albino rabbits, histopathological studies were attained to assure the safety of the formula. Finally, optimized VOR-MIP-CS could provide promising ocular drug delivery systems (DDS).

Polar pesticides can be primarily classified as fungicides, herbicides, and insecticides; their rich variety and low cost have led to their extensive utilization in agriculture. However, the overuse of polar pesticides can lead to environmental contamination, such as water or soil pollution, which can also increase the risk of pesticide exposure among human life directly, or indirectly through contact with animal and plant-derived food. There are considerable differences in the physical and chemical properties of polar pesticides, as well as their trace amounts in complex food and environmental samples, posing immense challenges to their accurate detection. As a kind of artificially prepared selective adsorbent, molecularly imprinted polymers (MIPs) possess specific recognition sites complementary to template molecules in terms of the spatial structure, size, and chemical functional groups. With many advantages such as easy preparation, low cost, as well as good chemical and mechanical stability, MIPs have been widely applied in sample pretreatment and the analysis of polar pesticide residues. MIPs are typically used as adsorption materials in solid phase extraction (SPE) methods, including magnetic solid phase extraction (MSPE), dispersed solid phase extraction (DSPE), and stir bar sorptive extraction (SBSE). To rapidly detect polar pesticide residues with high sensitivity, MIPs are also used in the preparation of fluorescent sensors and electrochemical sensors. Furthermore, MIPs can be employed as the substrate in surface-enhanced Raman spectroscopy and as the substrate for the ion source in mass spectrometry for polar pesticide residue analysis. Thus far, various molecularly imprinted materials have been reported for the efficient separation and analysis of polar pesticide residues in various complex matrices. However, there is no review that summarizes the recent advances in MIPs for the determination of polar pesticides. This review introduces imprinting strategies and polymerization methods for MIPs, and briefly summarizes some new molecular imprinting strategies and preparation technologies. The application of MIPs in recent years (particularly the last five years) to the detection of polar pesticide residues including neonicotinoids, organophosphorus, triazines, azoles, and urea is then systematically summarized. Finally, the future development direction and trends for MIPs are proposed considering existing challenges, with the aim of providing reference to guide future research on MIPs in the field of polar pesticide residue detection.

Photoresponsive surface molecularly imprinted polymers (PSMIPs) with controlled nanoshell thicknesses were synthesized using different amounts of precursor materials to determine the effects of polymer shell layer thickness on the separation and purification of 6-O-alpha-maltosyl-beta-cyclodextrin (Mal-β-CD). The physicochemical properties and adsorption and desorption capacities of PSMIPs with different shell thicknesses were studied. Interestingly, the uniform thickness of the imprinted polymer shell layer could be adjusted from 10 to 60 nm by varying the amount of polymerization precursors, and the average mesopore diameter of PSMIPs was not significantly affected by shell thickness. However, the removal efficiency and selective capacity of PSMIPs on Mal-β-CD were strongly correlated to their shell thickness. The adsorption behavior of PSMIPs on Mal-β-CD fitted well with the Langmuir adsorption model and pseudo-second-order kinetic model. Based on the obtained results, PSMIPs with a 30-nm imprinted layer were found to be an excellent adsorbent for Mal-β-CD separation, with an adsorption capacity of 18.12 mg/g. They can therefore be used for industrial chromatographic separations of Mal-β-CD in the future. PRACTICAL APPLICATION: This article clearly demonstrated that the shell thickness of core-shell molecularly imprinted materials affected the degree and rate of cyclodextrin separation. Determining the optimal thickness is of great significance for the material in the separation and purification of cyclodextrin.

Molecularly imprinted polymers (MIP) consist of a molecular recognition technology with applicability in different areas, including forensic chemistry. Among the forensic applications, the use of MIP in biological fluid analysis has gained prominence. Biological fluids are complex samples that generally require a pre-treatment to eliminate interfering agents to improve the results of the analyses. In this review, we address the development of this molecular imprinting technology over the years, highlighting the forensic applications of molecularly imprinted polymers in biological sample preparation for analysis of stimulant drugs such as cocaine, amphetamines, and nicotine.

A carbon paste electrode, modified with chitosan-based magnetic molecularly imprinted polymer (CS-MIP), was utilized as a highly sensitive electrochemical sensor for the determination of lactic acid (LA) in spoilage milk samples. The electrochemical measurements were indirectly performed by cyclic voltammetry and differential pulse voltammetry in the presence of K3[Fe(CN)6] as a redox probe. A decrease in the faradic current of the redox probe was imputed to the gate effect mechanism, which was related to electrical effects causing to disrupt the electronic transport pathway. The linear response ranges were 0.01–10.0 µM and 10.0–500.0 µM, and the detection limit was 0.005 µM. The electrochemical sensor was used for the determination of lactic acid in real milk samples with satisfactory results.

Today, we heavily rely on technology and increasingly utilize it to monitor our own health. The identification of sensitive, accurate biosensors that are capable of real-time cortisol analysis is one important potential feature for these technologies to aid us in the maintenance of our physical and mental wellbeing. Detection and quantification of cortisol, a well-known stress biomarker present in sweat, offers a noninvasive and potentially real-time method for monitoring anxiety. Molecularly imprinted polymers are attractive candidates for cortisol recognition elements in such devices as they can selectively rebind a targeted template molecule. However, mechanisms of imprinting and subsequent rebinding depend on the choice and composition of the prepolymerization mixture where the molecular interactions between the template, functional monomer, cross-linker, and solvent molecules are not fully understood. Here, we report the synthesis and evaluation of a molecularly imprinted polymer selective for cortisol detection. Molecular dynamics simulations were used to investigate the interactions between all components in the prepolymerization mixture of the as-synthesized molecularly imprinted polymer. Varying the component ratio of the prepolymerization mixture indicates that the number of cross-linker molecules relative to the template impacts the quality of imprinting. It was determined that a component ratio of 1:6:30 of cortisol, methacrylic acid, and ethylene glycol dimethacrylate, respectively, yields the optimal theoretical complexation of cortisol for the polymeric systems investigated. Experimental synthesis and rebinding results demonstrate an imprinting factor of up to 6.45. The trends in cortisol affinity predicted by molecular dynamics simulations of the prepolymerization mixture were also corroborated through experimental analysis of those modeled molecularly imprinted compositions, demonstrating the predictive capabilities of these simulations.

In this study, two types of CdSe, including nanoparticles and quantum dots, were synthesized. CdSe quantum dot nanoparticles were prepared via the hydrothermal technique at 140 °C for 8 h. The prep...

Unique restricted access media-magnetic molecularly imprinted polymers (RAM–MMIPs) were prepared as magnetic solid-phase extraction (MSPE) material for florfenicol (FF) and are combined with HPLC–UV to extract FF from fetal bovine serum samples. Under the optimization conditions, the resulting materials had a uniform imprinted layer, acceptable adsorption amounts (22.92 mg/g), rapid binding kinetics (80 min) and satisfactory selectivity. In addition, RAM–MMIPs presented satisfactory recoveries (95.6–102.1%), relative standard deviation (RSD) (2.7–3.9%) and lower limits of detection (LOD) (10.5 μg/L). The method was applied to the real samples. Compared with other reported methods, this method exhibits the advantages of simple, fast and, efficient operation, using a relatively small amount of the RAM–MMIPs adsorbent. The developed method can enrich FF from fetal bovine serum samples.

Molecularly imprinted polymer (MIP) beads imprinted with vitamin E (VE) were synthesized via a two-step swelling polymerization method, using methacrylic acid (MAA) and other functional monomers together with polystyrene (PS) microspheres as the substrate. In initial trials, different functional monomers were assessed, along with a variety of solvents and imprinting ratios. The MIPMAA sample exhibited the highest performance and was characterized and also assessed with regard to VE adsorption under various experimental conditions. This material exhibited reasonably good sphericity, porosity and stability, along with an excellent adsorption capacity of 46 mg/g. This was much higher than the value for the corresponding non-imprinted polymer made with the same monomer, and 20% higher than that for an acrylamide-based MIP synthesized using a precipitation polymerization method. The core-shell structured MIPMAA also demonstrated fast adsorption kinetics, a low pressure drop and good reusability in fixed bed experiments. The VE adsorption equilibrium, selectivity, kinetics, thermodynamics and regeneration capacity of this material were also examined and are reported herein.

Glycoproteins play crucial roles in many biological events such as protein folding, information transmission, nerve conduction, and molecular recognition. Some glycoproteins serve as disease biomarkers in clinical settings. However, selective detection of glycoprotein often faces great challenges, owing to its low abundance in complex biological samples. In this case, develop a highly sensitive and selective approach for glycoprotein detection is urgently needed. Molecularly imprinted polymers (MIPs) have proved to be an ideal absorbent material in detection and separation science. Herein, a novel biomass activated carbon–derived imprinted polymer (BAC@PEI/PBA/MIPs) was fabricated for selective recognition of glycoprotein. The as-prepared BAC@PEI/PBA/MIPs was synthesized using waste tea derived carbon as matrix, albumin chicken egg (OVA) as template, and dopamine as functional monomer. Branched polyethyleneimine (PEI) was covalently bonded on the BAC surface to increase the number of boronic acid moieties. Benefiting from the self-polymerization of dopamine and multi-boronic acid sites, a great number of recognition sites were presented under mild conditions. The static adsorption experiment showed that the BAC@PEI/PBA/MIPs exhibited a high binding capacity of 196.2 mg/g, rapid adsorption dynamics of 40 min, excellent selectivity and satisfactory reusability for OVA. Furthermore, the practicability of BAC@PEI/PBA/MIPs was verified by isolation of OVA from egg white. The good binding performance and facile preparation process make BAC@PEI/PBA/MIPs attractive for glycoprotein recognition, indicating its potential applications in biomedical research and clinical diagnostics.