Search

Molecularly imprinted polymers (MIPs) have gained growing interest among researchers worldwide, due to their key features that make these materials interesting candidates for implementation as receptors into sensor applications. In fact, MIP-based glucose sensors could overcome the stability issues associated with the enzymes present in commercial glucose devices. Various reports describe the successful development of glucose MIPs and their coupling to a wide variety of transducers for creating sensors that are able to detect glucose in various matrices. In this review, we have summarized and critically evaluated the different production methods of glucose MIPs and the different transducer technologies used in MIP-based glucose sensors, and analyzed these from a commercial point of view. In this way, this review sets out to highlight the most promising approaches in MIP-based sensing in terms of both manufacturing methods and readout technologies employed. In doing so, we aim at delineating potential future approaches and identifying potential obstacles that the MIP-sensing field may encounter in an attempt to penetrate the commercial, analytical market. [ABSTRACT FROM AUTHOR]

For many decades, synthetic receptors have been used as sensor elements and are a promising alternative to natural receptors, which, despite its great selectivity, are so complex and instable. The rational design of this kind of receptors is currently one of the most researched topics in molecular recognition. Molecular imprinted polymers (MIPs) have become a growing highlight in polymer chemistry, once they possess a wide range of applications and can be used in several environments, due to their high chemical and thermal stability. The aim of this study was to perform a rational design for the MIP preparation, for 3,4-methylenedioxymethamphetamine (MDMA) detection. The theoretical measurements were employed at several stages of the process, using DFT and B3LYP/6-31G(d,p) level of theory, by means of optimization and frequency calculations. Among the several functional monomers tested, the itaconic acid was the most appropriated for MIP preparation with MDMA template, and the proper molar ratio found theoretically was 3:1 (itaconic acid/MDMA). In the preparation of pre-polymerization complex, polar solvents were found to perform a better stabilization, mainly those which are not protic solvents. As cross-linking agents, the better results were obtained for trimethylolpropane trimethacrylate and ethylene glycol dimethacrylate molecules, respectively. Finally, selectivity tests showed a high affinity of the studied MIP for MDMA and chemically similar molecules. The proposal theoretical strategy yielded novel, experimentally testable hypotheses for the design of MIPs. Additionally, from the theoretical point of view, the set of computational analyses presented in this paper constitutes a very useful protocol to predict optimal experimental conditions, which can considerably reduce the time and cost on the MIPs preparation. [ABSTRACT FROM AUTHOR]

In this work, surface magnetic molecularly imprinted polymers (SMMIPs) were synthesized and used as artificial receptors in the dispersive magnetic solid phase extraction (DMSPE) for capturing potential neuronal nitric oxide synthase–post synaptic density protein-95 (nNOS–PSD-95) uncouplers, which is known as neuroprotection against stroke. Factors that affected selective separation and adsorption of the artificial receptors, such as the amount of template, the types of functional monomer and porogen solvents, and the molar ratio of template/functional monomer/cross-linker were optimized. The artificial receptors were also characterized using fourier transformed infrared, scanning electron microscope, thermal gravimetric analysis and physical property measurement systems. Multiple interactions between template and SMMIPs led to larger binding capacities, faster binding kinetics, quicker separation abilities and more efficient selectivity than the surface magnetic nonimprinted polymers (SMNIPs). The SMMIPs were successfully applied to capture potential nNOS–PSD-95 uncouplers from complex samples, and eight compounds were seized and confirmed rapidly when combined with HPLC and MS. The detection of the new nNOS–PSD-95 uncouplers ranged from 0.001 to 1.500 mg/mL with correlation coefficients of 0.9990–0.9995. The LOD and LOQ were 0.10–0.68 μg/mL and 0.47–2.11 μg/mL, respectively. The neuroprotective effect and co-immunoprecipitation test in vitro revealed that Emodin-1- O -β- d -glucoside, Rhaponticin, Gnetol and 2,3,5,4′-Tetrahydroxystilbene-2- O -β- d -glucoside have neuroprotective and uncoupling activities, and that they may be the new uncouplers of nNOS–PSD-95 [ABSTRACT FROM AUTHOR]

Abstract: A new type of molecularly imprinted polymer (MIP)-based fluorescent artificial receptor was developed by anchoring MIP on the surface of denatured bovine serum albumin (dBSA) modified CdTe quantum dots (QDs) using the surface molecular imprinting process. The approach combined the merits of molecular imprinting technology and the fluorescent property of the CdTe QDs. The dBSA was used not only to modify the surface defects of the CdTe QDs, but also as assistant monomer to create effective recognition sites. Three different proteins, namely lysozyme (Lyz), cytochrome c (Cyt) and methylated bovine serum albumin (mBSA), were tested as the template molecules and then the receptors were synthesized by sol–gel reaction (imprinting process). The results of fluorescence and binding experiments demonstrated the recognition performance of the receptors toward the corresponding template. Under optimum conditions, the linear range for Lyz was from 1.4×10−8 to 8.5×10−6 M, and the detection limit was 6.8nM. Moreover, the new artificial receptors were applied to separate and detect Lyz in real samples. This fluorescent artificial receptor may serve as a starting point in the design of highly effective synthetic fluorescent receptor for recognition of target protein. [Copyright &y& Elsevier]

Molecular Imprinting Technology (MIT) is a technique to design artificial receptors with a predetermined selectivity and specificity for a given analyte, which can be used as ideal materials in various application fields. Molecularly Imprinted Polymers (MIPs), the polymeric matrices obtained using the imprinting technology, are robust molecular recognition elements able to mimic natural recognition entities, such as antibodies and biological receptors, useful to separate and analyze complicated samples such as biological fluids and environmental samples. The scope of this review is to provide a general overview on MIPs field discussing first general aspects in MIP preparation and then dealing with various application aspects. This review aims to outline the molecularly imprinted process and present a summary of principal application fields of molecularly imprinted polymers, focusing on chemical sensing, separation science, drug delivery and catalysis. Some significant aspects about preparation and application of the molecular imprinting polymers with examples taken from the recent literature will be discussed. Theoretical and experimental parameters for MIPs design in terms of the interaction between template and polymer functionalities will be considered and synthesis methods for the improvement of MIP recognition properties will also be presented. [ABSTRACT FROM AUTHOR]

A robust and highly specific sensor based on electroactive molecularly imprinted polymer nanoparticles (nanoMIP) was developed. The nanoMIP tagged with a redox probe, combines both recognition and reporting capabilities. The developed nanoMIP replaces enzyme-mediator pairs used in traditional biosensors thus, offering enhanced molecular recognition for insulin, improving performance in complex biological samples, and yielding high stability. Also, most of existing sensors show poor performance after storage. To improve costs of the logistics and avoid the need of cold storage in the chain supply, we developed an alternative to biorecognition system that relies on nanoMIP. NanoMIP were computationally designed using "in-silico" insulin epitope mapping and synthesized by solid phase polymerisation. The characterisation of the polymer nanoparticles was performed by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform Infrared (FT-IR) and surface plasmon resonance (SPR). The electrochemical sensor was developed by chemical immobilisation of the nanoMIP on screen printed platinum electrodes. The insulin sensor displayed satisfactory performances and reproducible results (RSD = 4.2%; n = 30) using differential pulse voltammetry (DPV) in the clinically relevant concentration range from 50 to 2000 pM. The developed nanoMIP offers the advantage of large number of specific recognition sites with tailored geometry, as the resultant, the sensor showed high sensitivity and selectivity to insulin with a limit of detection (LOD) of 26 and 81 fM in buffer and human plasma, respectively, confirming the practical application for point of care monitoring. Moreover, the nanoMIP showed adequate storage stability of 168 days, demonstrating the robustness of sensor for several rounds of insulin analysis. • The molecularly imprinted polymer nanoparticles tagged with a redox probe, combines both recognition and reporting functions. • The electroactive nanoparticles system replaces enzyme-mediator pairs used in classic biosensors. • Nanoparticles were computationally designed to selectively bind insulin epitopes. • The sensor devised provides adequate selectivity, low cross-reactivity and high sensitivity in plasma. • This technology is robust and can be potentially applied to a broad range of targets. [ABSTRACT FROM AUTHOR]

Phenolic compounds are secondary metabolites frequently found in plants that exhibit many different effects on human health. Because of the relevant bioactivity, their identification and quantification in agro-food matrices as well as in biological samples are a fundamental issue in the field of quality control of food and food supplements, and clinical analysis. In this review, a critical selection of sensors and biosensors for rapid and selective detection of phenolic compounds is discussed. Sensors based on electrochemistry, photoelectrochemistry, fluorescence, and colorimetry are discussed including devices with or without specific recognition elements, such as biomolecules, enzymes and molecularly imprinted materials. Systems that have been tested on real matrices are prevalently considered but also techniques that show potential development in the field. [ABSTRACT FROM AUTHOR]