Preparation Of Molecularly Imprinted Polymers Research Articles

Computer simulation‐guided template selection for a molecularly imprinted polymer for selective trifluralin adsorption

AbstractTo meet selective adsorption toward trifluralin, a novel molecularly imprinted polymer (MIP) was fabricated by the dummy template molecular imprinting technology. First, computational simulation was performed to select a suitable dummy template, 3,5‐dinitro‐4‐methylbenzoic acid (T1), based on the maximum basis set superposition error (BSSE)‐corrected binding interaction energy (ΔE) of the monomer N‐vinylpyrrolidone (NVP)‐T1 complex and its structural overlap with trifluralin. Then, the MIP was prepared via the bulk polymerization. The adsorption experiments showed the MIP exhibited a trifluralin adsorption capacity of 5.1 mg g−1, an imprinting factor (IF) of 2.2, and short adsorption equilibrium time of 5 min. The adsorption of trifluralin conformed to the Freundlich adsorption (R2 = 0.985) and pseudo‐second‐order model (R2 = 0.999). In addition, the MIP exhibited selectivity to trifluralin over other adsorbents, including structural analogs (pendimethalin and oryzalin), pesticide (carbendazim), and nitrocompounds (nitrofurantoin, furazolidone, and furaltadone), with the selectivity factor (β) in the range of 1.2–3.0, respectively. In trifluralin/oryzalin mixture, the IF toward oryzalin was still as high as 1.9. The removal rate of the MIP to trifluralin in environmental water samples ranged from 90.08% to 99.04%. This study provides theoretical and experimental insights for the preparation of MIP using dummy templates.

Effect of Various Carbon Electrodes on MIP-Based Sensing Proteins Using Poly(Scopoletin): A Case Study of Ferritin.

Sensitivity in the sub-nanomolar concentration region is required to determine important protein biomarkers, e.g., ferritin. As a prerequisite for high sensitivity, in this paper, the affinity of the functional monomer to the macromolecular target ferritin in solution was compared with the value for the respective molecularly imprinted polymer (MIP)-based electrodes, and the influence of various surface modifications of the electrode was investigated. The analytical performance of ferritin sensing was investigated using three different carbon electrodes (screen-printed carbon electrodes, single-walled-carbon-nanotube-modified screen-printed carbon electrodes, and glassy carbon electrodes) covered with a scopoletin-based MIP layer. Regardless of the electrode type, the template molecule ferritin was mixed with the functional monomer scopoletin, and electropolymerization was conducted using multistep amperometry. All stages of MIP preparation were followed by evaluating the diffusional permeability of the redox marker ferricyanide/ferrocyanide through the polymer layer by differential pulse voltammetry. The best results were obtained with glassy carbon electrodes. The MIP sensor responded up to 0.5 µM linearly with a Kd of 0.30 µM. Similar results were also obtained in solution upon the interaction of scopoletin and ferritin using fluorescence spectroscopy, resulting in the quenching of the scopoletin signal, with a calculated Kd of 0.81 µM. Moreover, the binding of 1 µM ferritin led to 49.6% suppression, whereas human serum albumin caused 8.6% suppression.

Electrochemically Synthesized MIP Sensors: Applications in Healthcare Diagnostics.

Early-stage detection and diagnosis of diseases is essential to the prompt commencement of treatment regimens, curbing the spread of the disease, and improving human health. Thus, the accurate detection of disease biomarkers through the development of robust, sensitive, and selective diagnostic tools has remained cutting-edge scientific research for decades. Due to their merits of being selective, stable, simple, and having a low preparation cost, molecularly imprinted polymers (MIPs) are increasingly becoming artificial substitutes for natural receptors in the design of state-of-the-art sensing devices. While there are different MIP preparation approaches, electrochemical synthesis presents a unique and outstanding method for chemical sensing applications, allowing the direct formation of the polymer on the transducer as well as simplicity in tuning the film properties, thus accelerating the trend in the design of commercial MIP-based sensors. This review evaluates recent achievements in the applications of electrosynthesized MIP sensors for clinical analysis of disease biomarkers, identifying major trends and highlighting interesting perspectives on the realization of commercial MIP-endowed testing devices for rapid determination of prevailing diseases.

Microwave‐assisted molecularly imprinted polymer synthesis for chemometric and rebinding mechanism of drug release applications

AbstractSynthesis of molecularly imprinted polymers (MIP) has gained wide interest as drug delivery vehicles in recent years. The conventional one‐variable‐at‐a‐time method for determining the best formulation ratio of MIP templates is resource‐ and time‐consuming. Thus, this study focused on the response surface methodology optimization of the best formulation for MIP preparation using methacrylic acid and divinylbenzene as functional monomer and cross‐linker, respectively. Two preparation systems were studied, namely microwave (MW)‐assisted and conventional synthesis. The MIPs showed spherical particles with smaller particle sizes (500 nm–1.45 μm) and higher yields (0.5–1.2 g) via MW‐assisted synthesis as compared to the conventional synthesis (size 660 nm–3.65 μm, yield 0.5–1.15 g). MW‐assisted synthesis is faster and more efficient to synthesize controlled shapes and sizes of MIP particles. The rebinding properties of prepared MIP via MW were higher (7.15 ± 0.02 mg/g) than conventional synthesis (3.00 ± 0.31 mg/g). The empirical models were developed to correlate the output response of rebinding properties and input variables. The analysis of variance confirmed that experimental data were superbly fitted to the proposed response models. A satisfactory correlation between the experimental and predicted values was obtained by both MIP prepared via MW‐assisted and conventional synthesis.

Molecularly Imprinted Polymers Using Yeast as a Supporting Substrate.

Molecularly imprinted polymers (MIPs) have gained significant attention as artificial receptors due to their low cost, mild operating conditions, and excellent selectivity. To optimize the synthesis process and enhance the recognition performance, various support materials for molecular imprinting have been explored as a crucial research direction. Yeast, a biological material, offers advantages such as being green and environmentally friendly, low cost, and easy availability, making it a promising supporting substrate in the molecular imprinting process. We focus on the preparation of different types of MIPs involving yeast and elaborate on the specific roles it plays in each case. Additionally, we discuss the advantages and limitations of yeast in the preparation of MIPs and conclude with the challenges and future development trends of yeast in molecular imprinting research.

A molecularly imprinted polymer for microextraction by packed sorbent of sulfonylureas herbicides from corn samples

A molecularly imprinted polymer (MIP) was synthesized and assessed as a selective extraction phase in the microextraction by packed sorbent (MEPS) of sulfonylureas herbicides (SUHs) — Thifensulfuron, Chlorosulfuron, Tribenuron, and Bensulfuron — from grounded corn samples. Bensulfuron was employed as the template for the MIP preparation. MIP particles were chemically and structurally characterized. Distribution (Kd), selectivity (k), and relative selectivity (k') coefficients were estimated using binary mixtures of bensulfuron/betazon and bensulfuron/prometon. The most significant parameters affecting the MEPS performance were systematically studied in univariate and multivariate experiments. Analyses were performed by liquid chromatography coupled to time-of-flight mass spectrometry (LC-ToF). Under selected conditions, the developed MIP-MEPS-LC-ToF method demonstrated suitable analytical confidence and reliability. Determination coefficients (r2) higher than 0.9940, and limits of detection (LODs) of 2.5 µg kg-1 were obtained. Intra- and interday precision was lower than 14.2%, and accuracy ranged between 89.6% and 113.6%. The synthesized MIP demonstrated enhanced selectivity and higher SUHs uptake capability compared to the non-imprinted polymer (NIP) and tested commercial sorbents. Besides, the method is a cheap, feasible, and environmentally friendly analytical tool. A single MEPS device packed with 1.0 mg of MIP was reused more than 180 times without loss in its extraction capabilities.

Vapor-Phase Synthesis of Molecularly Imprinted Polymers on Nanostructured Materials at Room-Temperature.

Molecularly imprinted polymers (MIPs) have recently emerged as robust and versatile artificial receptors. MIP synthesis is carried out in liquid phase and optimized on planar surfaces. Application of MIPs to nanostructured materials is challenging due to diffusion-limited transport of monomers within the nanomaterial recesses, especially when the aspect ratio is >10. Here, the room temperature vapor-phase synthesis of MIPs in nanostructured materials is reported. The vapor phase synthesis leverages a >1000-fold increase in the diffusion coefficient of monomers in vapor phase, compared to liquid phase, to relax diffusion-limited transport and enablethe controlled synthesis of MIPs also in nanostructures with high aspect ratio. As proof-of-concept application, pyrrole is used as the functional monomer thanks to its large exploitation in MIP preparation; nanostructured porous silicon oxide (PSiO2 ) is chosen to assess the vapor-phase deposition of PPy-based MIP in nanostructures with aspect ratio >100; human hemoglobin (HHb) is selected as the target molecule for the preparation of a MIP-based PSiO2 optical sensor. High sensitivityand selectivity, low detection limit, high stability and reusability are achieved in label-free optical detection of HHb, also in human plasma and artificial serum. The proposed vapor-phase synthesis of MIPs is immediately transferable to other nanomaterials, transducers, and proteins.

Molecularly Imprinted Plasmonic Sensors for the Determination of Environmental Water Contaminants: A Review

The scarcity of clean water leads to the exploration of the possibility of using treated wastewater. However, monitoring campaigns have proven the presence of emerging contaminants, such as pharmaceuticals, pesticides and personal care products, not only in trace amounts. Various analytical methodologies have been developed over the last years for the quantification of these compounds in environmental waters. Facing the need to achieve a higher sensitivity, fast response and practical use via miniaturization, the potential of plasmonic sensors has been explored. Through the introduction of molecularly imprinted polymers (MIPs) as recognition elements, MIP-based plasmonic sensors seem to be a good alternative for monitoring a wide range of analytes in water samples. This work attempts to provide a general overview of this form of sensor, which has been reported as being able to sense different contaminants in waters using surface plasmon resonance (SPR) and surface-enhanced Raman-scattering (SERS) techniques. Particular emphasis is given to the fabrication/recognition procedure, including the preparation of MIPs and the use of metals and nanomaterials to increase the performance characteristics of the sensors.

Preparation and Application of Polymeric Molecularly Imprinted Adsorbents in Accordance with the Principles of Green Chemistry

Molecularly imprinting technology is a suitable tool for the development of selective materials for the isolation and separation of substances, and targeted use. The aim of this paper was to compile an overview of current trends in the preparation of MIP (Molecularly Imprinted Polymers). We focused on the implementation of ecologically acceptable solutions in the procedures for the fabrication and application of MIP, mainly for the purposes of chemical analyses. Theoretical approaches and simulations for the selection of optimal components of the polymerization mixture, the application of ultrasonic and microwave light in MIP synthesis, as well as microextraction procedures for the preparation of complex samples for analysis are successfully applied in analytical methods based on MIP adsorbents. While the use of low transition temperature mixtures (deep eutectic solvents, ionic liquids) and biomass components as a replacement or modification of porogens, functional and cross-linking monomers or other components of the polymerization mixture can help to transform the polymerization processes into more environment-friendly ones, it still requires an investigation of the synthesis mechanisms and their influence on the properties of the prepared MIPs.

Magnetic Nanoparticles Molecularly Imprinted Polymers: A Review

Abstract: The molecularly imprinted polymers (MIPs) technology, which has been around since the 1970s, has grown in popularity in recent decades. MIPs have shown to be a useful approach for determining target molecules in complicated matrices containing other structurally similar and related chemicals. Despite MIPs have intrinsic polymer features such as stability, robustness, and low-cost production, traditional MIPs have a number of drawbacks. Surface molecular imprinting appears to be an alternative approach that can address some of the drawbacks of traditional MIP by anchoring shells to the surface of matrix carriers such as nanoparticles. The incorporation of nanoparticles into the polymeric structure of MIPs can improve their properties or provide novel capabilities. Magnetic nanoparticles have been widely explored for their separation and extraction capability. Magnetic components in MIP can help develop a regulated rebinding process, allowing magnetic separation to substitute centrifugation and filtration stages in a simple and cost-effective strategy. Polymers are created directly on the surface of a magnetic substrate to create a unique material termed magnetic molecularly imprinted polymer (MMIP). These materials have been widely used to extract molecules from complex matrices in a variety of applications, especially in environmental, food, and biological studies. This paper seeks to summarize and discuss the nanoparticle synthesis and magnetic nanoparticle combination in the MIP preparation. The novel applications of MMIP in environmental, food, and biological analysis are also discussed in this paper.

Preparation and computational investigation of molecular imprinted polymers for Clidinium Bromide

Molecular imprinted polymers (MIPs) are polymers that possess recognition sites specific for a predetermined target molecule (Template). Inspired by the idea of biological natural receptors, they behave like synthetic molecular recognition elements. They have been developed into a promising tool in several crucial applications, including analytical methods, drug delivery, and catalysis. The non-covalent imprinting is more commonly used approach in the preparation of MIPs because of its simplicity. In this approach, intermolecular interactions between the template molecule (T) and the functional monomer (FM) are the forces that govern the performance of the resulting MIP. Hence, studying these interactions is very important to elucidate and understand the imprinting mechanism. This paper focuses on preparation of two MIPs for a Clidinium Bromide (CB), using two different types of FMs. These MIPs are characterized by using IR and SEM techniques. Adsorption isotherm properties to CB are assayed for them. Then the structures of the pre-polymerization complexes of prepared MIPs were investigated using Density Functional Theory (DFT) calculations at B3LYP/6-31G level in a vacuum and other media. Finally, Bader's Quantum Theory of Atoms in Molecules (QTAIM) was used to prove the existence and nature of intermolecular interactions between CB and FM. The theoretical results were in complete agreement with experiments and indicated that the use of AM as FM is preferred over MA in the MIP preparation for CB.

Potentiometric sensor based on a computationally designed molecularly imprinted receptor

Molecularly imprinted polymer (MIP)-based polymeric membrane potentiometric sensors are ideal candidates for detection of organic species. The development of such sensors has opened new attractive horizons for potentiometric sensing. However, it should be noted that in the preparation of these MIP receptors, the selection of the functional monomer usually depends on empirical trial- and error-based optimization, which involves tedious and time-consuming experiments. In this work, the computer-aided design and synthesis of an MIP receptor are applied in the fabrication of an MIP-based potentiometric sensor. The density functional theory calculation with the B3LYP model and 6-31G(d) basis set is used to study the interactions between the functional monomer and template molecules. The binding energies of the complexations between the template molecule and different functional monomers are used as a criterion for the selection of the proper monomer. The designed MIP is then synthesized and employed as the receptor for the fabrication of the potentiometric sensor. As a proof-of-concept experiment, the antibiotic sulfadiazine has been selected as a model and 4 functional monomers, 2-hydroxyethyl methacrylate, methyl methacrylate, N-isopropylacrylamide and N-phenylacrylamide, have been chosen. The designed MIP-based sensor exhibits excellent sensitivity with a linear range of 1–10 μM and also shows a good selectivity. We believe that the proposed computer-aided synthesis technique for the MIP receptor selection can provide a general and facile way to replace the traditional empirical MIP preparation method in the fabrication of MIP-based electrochemical and optical sensors.

Synthesis of water-compatible noncovalent imprinted microspheres for acidic or basic biomolecules designed based on molecular dynamics

Molecularly imprinted polymers (MIPs), as selective adsorbents, have shown great potential in the selective separation and enrichment of trace targets from complex components. However, the preparation of MIPs with specific recognition in aqueous solution is facing great challenges, thus largely limiting their application scope in selective separation and analysis of water samples. Aiming at the challenges and problems in the above-mentioned molecularly imprinting technology, a new rational method of water-compatible noncovalent imprinted microspheres was proposed. In the method, functional monomers were screened based on molecular dynamics (MD) and then water-compatible spherical MIPs were prepared with a modified suspension polymerization method. To verify this method, a basic molecule (spiramycin) and an acidic molecule (chenodeoxycholic acid) were selected as templates. After the characterization of the synthesized polymers, the adsorption capacities of SPM-MIP and CDCA-MIP were tested in an aqueous environment. In adsorption experiments, CDCA-MIP and SPM-MIP showed higher adsorption capacities and the imprinting factors of CDCA-MIP and SPM-MIP reached 3.96 and 2.51, respectively. Due to the imprinting effect, the prepared SPM-MIP and CDCA-MIP had selectivity. Moreover, SPM-MIP and CDCA-MIP showed the strong protein adsorption resistance in an aqueous medium. These results confirmed that the reasonable design was feasible and significant in designing water-compatible non-covalent imprinted polymers. In addition, the screening strategy of imprinting systems proposed in this study has certain universality and can be widely used to screen various imprinting systems. • 1、Theoretical investigation on the noncovalent MIPs used in aqueous environment. • 2、A modified suspension polymerization was proposed to synthesize CDCA-MIP and. • SPM-MIP. • 3、CDCA-MIP and SPM-MIP had high adsorption capacity, selectivity and reusability. • 4、CDCA-MIP and SPM-MIP showed strong anti-protein adsorption in aqueous environment. .

Molecularly Imprinted Solid Phase Extraction Strategy for Quinic Acid.

Quinic acid (QA) and its ester conjugates have been subjected to in-depth scientific investigations for their antioxidant properties. In this study, molecularly imprinted polymers (MIPs) were used for selective extraction of quinic acid (QA) from coffee bean extract. Computational modelling was performed to optimize the process of MIP preparation. Three different functional monomers (allylamine, methacrylic acid (MAA) and 4-vinylpyridine (4-VP)) were tested for imprinting. The ratio of each monomer to template chosen was based on the optimum ratio obtained from computational studies. Equilibrium rebinding studies were conducted and MIP C, which was prepared using 4-VP as functional monomer with template to monomer ratio of 1:5, showed better binding performance than the other prepared MIPs. Accordingly, MIP C was chosen to be applied for selective separation of QA using solid-phase extraction. The selectivity of MIP C towards QA was tested versus its analogues found in coffee (caffeic acid and chlorogenic acid). Molecularly imprinted solid-phase extraction (MISPE) using MIP C as sorbent was then applied for selective extraction of QA from aqueous coffee extract. The applied MISPE was able to retrieve 81.918 ± 3.027% of QA with a significant reduction in the amount of other components in the extract.

Recent Trends in the Development of Carbon-Based Electrodes Modified with Molecularly Imprinted Polymers for Antibiotic Electroanalysis

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.

Advances in fabrication of molecularly imprinted electrochemical sensors for detection of contaminants and toxicants

Worldwide growing concerns about water contamination and pollution have increased significant interest in trace level sensing of variety of contaminants. Thus, there is demand for fabrication of low cost, miniaturized sensing device for in-situ detection of contaminants from the complex environmental matrices capable of providing selective and sensitive detection. Molecularly imprinted polymers (MIPs) has portrayed a substantial potential for selective recognition of various toxicants from a variety of environmental matrices, thus widely used as artificial recognition element in the electrochemical sensors (ECS) owing to their chemical stability, easy and low cost synthesis. The combination of nanomaterials modifiers with MIPs has endowed MIP-ECS with significantly improved sensing performance in the recent years, as the nanomaterial provide properties such as increased surface area, increased conductivity and electrocatalytic activity with enhanced electron transport phenomena, whereas MIPs provide selective recognition effect.In the present review, we have summarized the advances of MIP-ECS electrochemical sensors reported in last six years (2017–2022) for sensing of variety of contaminates including drugs, metal ions, hormones and emerging contaminates. Scope of computational modelling in design of sensitive and selective MIP-ECS is reviewed. We have focused particularly on the synthetic protocols for MIPs preparation including bulk, precipitation, electropolymerization, sol-gel and magnetic MIPs. Moreover, use of various nanomaterial as modifiers and sensitizers and their effects on the sensing performance of resulting MIP-ECS is described. Finally, the potential challenges and future prospects in the research area of MIP-ECS have been discussed.

Antifouling ionic liquid doped molecularly imprinted polymer-based ratiometric electrochemical sensor for highly stable and selective detection of zearalenone

Zearalenone (ZEN) is a nonsteroidal estrogenic mycotoxin, and its accurate detection in complex biological samples is still a challenge. Herein, an antifouling ratiometric electrochemical sensor has been developed for its detection. In this system, black phosphorus-graphene oxide is used as substrate to amplify the signal; ionic liquid doped molecularly imprinted polymer (MIP) endows the sensing surface not only high recognition ability but also high capability to resist nonspecific adsorption. During MIP preparation a magnetic field is introduced to regulate polymer structure for improving the recognition efficiency of the sensor. The signals of ZEN and poly methylene blue (MB) serve as response signal and internal reference signal, respectively. The peak current of ZEN increases with the increase of ZEN concentration, while the peak current of poly(MB) decreases simultaneously; their ratio changes with ZEN concentration variation. The obtained ratiometric sensor shows a wide linear response range of 0.05–13 μM and a low limit of detection of 12.7 nM (S/N = 3). Furthermore, it has high selectivity, stability and reproducibility, thanks to the advanced antifouling MIP and the built-in correction of poly(MB). The sensor has been successfully applied to determine ZEN in human serum.

High Mannose-Specific Aptamers for Broad-Spectrum Virus Inhibition and Cancer Targeting

High Mannose-Specific Aptamers for Broad-Spectrum Virus Inhibition and Cancer Targeting

Thiourea derivatives acting as functional monomers of As(Ш) molecular imprinted polymers: A theoretical and experimental study on binding mechanisms

Thiourea derivatives are expected to be potential monomers of As(Ш) molecular imprinted polymers (MIPs) which are used to specifically recognize As(Ш). However, the specific recognition and binding mechanisms between template and monomers are unclear, which limits the practical applications of MIPs in As(Ш)detection. In this work, density functional theory (DFT) calculations, molecular dynamics (MD) simulations and experimental methods were jointly applied to explore the binding interactions between H3AsO3 and thiourea derivatives and environmental factors influences, aiming to find out the best monomer and optimal preparation conditions for H3AsO3 MIPs. Among five monomer candidates, (2, 6-difluorophenyl) thiourea (FT) was calculated to be the most potential one, while allyl thiourea (AT) was the second choice. Configurations of the most stable binding complexes were found out. The optimal solvent was found to be toluene and the bindings were more favorable at pH 7.5 in aqueous solution. Besides, EGDMA was proved as the best cross-linker with the optimal ratio of template: monomer: cross-linker= 2:3:20. Moreover, the binding interactions were identified to be hydrogen bonds, and the non-covalent nature was revealed. These findings provide references for efficient design and preparation of good-performance H3AsO3 MIPs, which can be used to detect and remove As(Ш) from environment.

Development of fluorescence sensor and test paper based on molecularly imprinted carbon quantum dots for spiked detection of domoic acid in shellfish and lake water

Excessive levels of domoic acid (DA) in edible shellfish and water can seriously threaten human health and even cause death. Herein, we have developed a fluorescence sensor and test paper based on molecularly imprinted carbon quantum dots (B-CDs@MIPs) for DA analysis. In this research, the prepared carbon quantum dots (B-CDs) with good optical properties were used as the sensitive fluorescent signal probes, and the molecularly imprinted polymers (MIPs) instead of biological antibodies were employed as the specific recognition components because of their high stability and low cost. Due to the shielding effect of imprinted silicon layer and the influence of modified groups introduced in the MIPs preparation process, the fluorescence signal of B-CDs in MIPs is inhibited. Interestingly, the DA can cause the partial recovery of the fluorescence intensity of B-CDs@MIPs by passivating the modified groups on the surface of B-CDs in MIPs. According to this principle, the designed fluorescence sensor reveals outstanding stability, super anti-interference ability, and excellent sensitivity, with the detection limit down to 10 nM. The sensor has been successfully applied to the rapid and accurate spiked analysis of DA in edible shellfish and lake water, providing excellent recoveries. More importantly, the designed inexpensive and easy-to-operate fluorescent test paper can realize preliminary qualitative analysis of DA on site by naked eye, indicating its promising application potential in food and environmental analysis.