Unveiling the potential of molecular imprinting polymer-based composites in the discovery of advanced drug delivery carriers

Molecularly imprinted polymers (MIPs) are polymeric matrices that can mimic natural recognition entities, such as antibodies and biological receptors. Molecular imprinting of therapeutics is very appealing in the design of drug delivery systems since the specific and selective binding sites created within the polymeric matrix turn these complex structures into value-added carriers with tunable features, notably high drug-loading capacity and good control of payload release. MIPs possess considerable promise as synthetic recognition elements in 'theranostics'. Moreover, the high affinity and specificity of MIPs make them more advantageous than other polymer-based nanocomposites. This review summarizes the present state-of-the-art of MIP-based delivery systems for the targeted delivery of bioactives, with current challenges and future perspectives.

The Multi-Challenges of the Multi-Ion-Imprinted Polymer Synthesis

Multi-ion-imprinted polymers (MIIPs) are materials with a wide range of applications mainly focused on environmental recovery, mining, technology, sensors, etc. MIIPs can incorporate ions such as heavy metals, transition metals, rare earth elements, radionuclides, and other types of ions. The chemical structures of MIIPs can be designed for different purposes and with certain morphologies, such as gels, crystals, or powders, and the surface area and porosity are also considered. All these properties provide the material with several desirable characteristics, like high selectivity, high specificity, adequate efficiency, good stability, the possibility of reusability, and strategy technology adaptation. In this review, we show the multitude of challenges of multi-ion imprinted polymer chemical synthesis based on the different and interesting methods reported previously.

Sensors Based on Molecularly Imprinted Polymers in the Field of Cancer Biomarker Detection: A Review

Biomarkers play a pivotal role in the screening, diagnosis, prevention, and post-treatment follow-up of various malignant tumors. In certain instances, identifying these markers necessitates prior treatment due to the complex nature of the tumor microenvironment. Consequently, advancing techniques that exhibit selectivity, specificity, and enable streamlined analysis hold significant importance. Molecularly imprinted polymers (MIPs) are considered synthetic antibodies because they possess the property of molecular recognition with high selectivity and sensitivity. In recent years, there has been a notable surge in the investigation of these materials, primarily driven by their remarkable adaptability in terms of tailoring them for specific target molecules and integrating them into diverse analytical technologies. This review presents a comprehensive analysis of molecular imprinting techniques, highlighting their application in developing sensors and analytical methods for cancer detection, diagnosis, and monitoring. Therefore, MIPs offer great potential in oncology and show promise for improving the accuracy of cancer screening and diagnosis procedures.

Recent Advances in Molecular Imprinting for Proteins on Magnetic Microspheres

The separation of proteins in biological samples plays an essential role in the development of disease detection, drug discovery, and biological analysis. Protein imprinted polymers (PIPs) serve as a tool to capture target proteins specifically and selectively from complex media for separation purposes. Whereas conventional molecularly imprinted polymer is time-consuming in terms of incubation studies and solvent removal, magnetic particles are introduced using their magnetic properties for sedimentation and separation, resulting in saving extraction and centrifugation steps. Magnetic protein imprinted polymers (MPIPs), which combine molecularly imprinting materials with magnetic properties, have emerged as a new area of research hotspot. This review provides an overview of MPIPs for proteins, including synthesis, preparation strategies, and applications. Moreover, it also looks forward to the future directions for research in this emerging field.

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.

On-Demand, Reversible, Ultrasensitive Polymer Membrane Based on Molecular Imprinting Polymer

The development of in vivo, longitudinal, real-time monitoring devices is an essential step toward continuous, precision health monitoring. Molecularly imprinted polymers (MIPs) are popular sensor capture agents that are more robust than antibodies and have been used for sensors, drug delivery, affinity separations, assays, and solid-phase extraction. However, MIP sensors are typically limited to one-time use due to their high binding affinity (>10⁷ M^-1) and slow-release kinetics (<10^-4 μM/sec). To overcome this challenge, current research has focused on stimuli-responsive MIPs (SR-MIPs), which undergo a conformational change induced by external stimuli to reverse molecular binding, requiring additional chemicals or outside stimuli. Here, we demonstrate fully reversible MIP sensors based on electrostatic repulsion. Once the target analyte is bound within a thin film MIP on an electrode, a small electrical potential successfully releases the bound molecules, enabling repeated, accurate measurements. We demonstrate an electrostatically refreshed dopamine sensor with a 760 pM limit of detection, linear response profile, and accuracy even after 30 sensing-release cycles. These sensors could repeatedly detect <1 nM dopamine released from PC-12 cells in vitro, demonstrating they can longitudinally measure low concentrations in complex biological environments without clogging. Our work provides a simple and effective strategy for enhancing the use of MIPs-based biosensors for all charged molecules in continuous, real-time health monitoring and other sensing applications.

Advances in Stimuli-responsive Hydrogels for Tissue Engineering and Regenerative Medicine Applications: A Review Towards Improving Structural Design for 3D Printing

The physicochemical properties of polymeric hydrogels render them attractive for the development of 3D printed prototypes for tissue engineering in regenerative medicine. Significant effort has been made to design hydrogels with desirable attributes that facilitate 3D printability. In addition, there is significant interest in exploring stimuli-responsive hydrogels to support automated 3D printing into more structurally organised prototypes such as customizable bio-scaffolds for regenerative medicine applications. Synthesizing stimuli-responsive hydrogels is dependent on the type of design and modulation of various polymeric materials to open novel opportunities for applications in biomedicine and bio-engineering. In this review, the salient advances made in the design of stimuli-responsive polymeric hydrogels for 3D printing in tissue engineering are discussed with a specific focus on the different methods of manipulation to develop 3D printed stimuli-responsive polymeric hydrogels. Polymeric functionalisation, nano-enabling and crosslinking are amongst the most common manipulative attributes that affect the assembly and structure of 3D printed bio-scaffolds and their stimuli- responsiveness. The review also provides a concise incursion into the various applications of stimuli to enhance the automated production of structurally organized 3D printed medical prototypes.

Green Chemistry and Molecularly Imprinted Membranes

Technological progress has made chemistry assume a role of primary importance in our daily life. However, the worsening of the level of environmental pollution is increasingly leading to the realization of more eco-friendly chemical processes due to the advent of green chemistry. The challenge of green chemistry is to produce more and better while consuming and rejecting less. It represents a profitable approach to address environmental problems and the new demands of industrial competitiveness. The concept of green chemistry finds application in several material syntheses such as organic, inorganic, and coordination materials and nanomaterials. One of the different goals pursued in the field of materials science is the application of GC for producing sustainable green polymers and membranes. In this context, extremely relevant is the application of green chemistry in the production of imprinted materials by means of its combination with molecular imprinting technology. Referring to this issue, in the present review, the application of the concept of green chemistry in the production of polymeric materials is discussed. In addition, the principles of green molecular imprinting as well as their application in developing greenificated, imprinted polymers and membranes are presented. In particular, green actions (e.g., the use of harmless chemicals, natural polymers, ultrasound-assisted synthesis and extraction, supercritical CO2, etc.) characterizing the imprinting and the post-imprinting process for producing green molecularly imprinted membranes are highlighted.

Molecularly Imprinted Polymers (MIPs) in Sensors for Environmental and Biomedical Applications: A Review

Molecular imprinted polymers are custom made materials with specific recognition sites for a target molecule. Their specificity and the variety of materials and physical shapes in which they can be fabricated make them ideal components for sensing platforms. Despite their excellent properties, MIP-based sensors have rarely left the academic laboratory environment. This work presents a comprehensive review of recent reports in the environmental and biomedical fields, with a focus on electrochemical and optical signaling mechanisms. The discussion aims to identify knowledge gaps that hinder the translation of MIP-based technology from research laboratories to commercialization.

The promising use of nano-molecular imprinted templates for improved SARS-CoV-2 detection, drug delivery and research

Molecular imprinting (MI) is a technique that creates a template of a molecule for improving complementary binding sites in terms of size and shape to a peptide, protein, bacteria, mammalian cell, or virus on soft materials (such as polymers, hydrogels, or self-assembled materials). MI has been widely investigated for over 90 years in various industries but is now focused on improved tissue engineering, regenerative medicine, drug delivery, sensors, diagnostics, therapeutics and other medical applications. Molecular targets that have been studied so far in MI include those for the major antigenic determinants of microorganisms (like bacteria or viruses) leading to innovations in disease diagnosis via solid-phase extraction separation and biomimetic sensors. As such, although not widely investigated yet, MI demonstrates much promise for improving the detection of and treatment for the current Coronavirus Disease of 2019 (COVID-2019) pandemic as well as future pandemics. In this manner, this review will introduce the numerous applications of MI polymers, particularly using proteins and peptides, and how these MI polymers can be used as improved diagnostic and therapeutic tools for COVID-19.

Recent Advances in Micro/Nanomaterial-Based Aptamer Selection Strategies

Aptamers are artificial nucleic acid ligands that have been employed in various fundamental studies and applications, such as biological analyses, disease diagnostics, targeted therapeutics, and environmental pollutant detection. This review focuses on the recent advances in aptamer discovery strategies that have been used to detect various chemicals and biomolecules. Recent examples of the strategies discussed here are based on the classification of these micro/nanomaterial-mediated systematic evolution of ligands by exponential enrichment (SELEX) platforms into three categories: bead-mediated, carbon-based nanomaterial-mediated, and other nanoparticle-mediated strategies. In addition to describing the advantages and limitations of the aforementioned strategies, this review discusses potential strategies to develop high-performance aptamers.

Detection of canine and equine procalcitonin for sepsis diagnosis in veterinary clinic by the development of novel MIP-based SPR biosensors

Procalcitonin (PCT) has emerged as a promising biomarker for the rapid identification of sepsis both in human and veterinary medicine. Nevertheless, the only analytical method currently available for the detection of PCT in veterinary species, is represented by immunoassays, useful only for research purposes. In this work, we report the development of two biosensors which utilize molecularly imprinted polymers (MIPs) for the detection of canine and equine PCT. Dopamine (DA) and norepinephrine (NE) were used as monomers for the synthesis of the MIP films on surface plasmon resonance (SPR) gold chips and the imprinting efficiency of canine and equine PCT in terms of binding affinity toward the analyte, selectivity, and sensitivity were compared. After optimization in buffer conditions, PCTs calibration was successfully achieved also in animal plasma, with good specificity and reproducibility. More effective protein binding and imprinting was obtained with polynorepinephrine (PNE) for both PCTs, and the SPR biosensors were able to detect the biomarkers in plasma with a LOD of 15 ng mL^-1 and 30 ng mL^-1 respectively for equine and canine PCT.

An Overview of Bio-Inspired Intelligent Imprinted Polymers for Virus Determination

The molecular imprinting polymers (MIPs) have shown their potential in various applications including pharmaceuticals, chemical sensing and biosensing, medical diagnosis, and environmental related issues, owing to their artificial selective biomimetic recognition ability. Despite the challenges posed in the imprinting and recognition of biomacromolecules, the use of MIP for the imprinting of large biomolecular oragnism such as viruses is of huge interest because of the necessity of early diagnosis of virus-induced diseases for clinical and point-of-care (POC) purposes. Thus, many fascinating works have been documented in which such synthetic systems undoubtedly explore a variety of potential implementations, from virus elimination, purification, and diagnosis to virus and bacteria-borne disease therapy. This study is focused comprehensively on the fabrication strategies and their usage in many virus-imprinted works that have appeared in the literature. The drawbacks, challenges, and perspectives are also highlighted.

Molecular Imprinting Strategies for Tissue Engineering Applications: A Review

Tissue Engineering (TE) represents a promising solution to fabricate engineered constructs able to restore tissue damage after implantation. In the classic TE approach, biomaterials are used alongside growth factors to create a scaffolding structure that supports cells during the construct maturation. A current challenge in TE is the creation of engineered constructs able to mimic the complex microenvironment found in the natural tissue, so as to promote and guide cell migration, proliferation, and differentiation. In this context, the introduction inside the scaffold of molecularly imprinted polymers (MIPs)—synthetic receptors able to reversibly bind to biomolecules—holds great promise to enhance the scaffold-cell interaction. In this review, we analyze the main strategies that have been used for MIP design and fabrication with a particular focus on biomedical research. Furthermore, to highlight the potential of MIPs for scaffold-based TE, we present recent examples on how MIPs have been used in TE to introduce biophysical cues as well as for drug delivery and sequestering.

Hollow molecularly imprinted fluorescent sensor using europium complex as functional monomer for the detection of trace 2,4,6-trichlorophenol in real water samples

As an important environmental indicator, 2,4,6-trichlorophenol (2,4,6-TCP) was proved extremely harmful to human body. In this article, hollow molecularly imprinted fluorescent polymers (@MIPs) for the selective detection of 2,4,6-TCP were devised and fabricated by sacrificial skeleton method based on SiO₂ nanoparticles. As the most innovation, highly luminescent europium complex Eu(MAA)₃phen played the role of both fluorophores and functional monomers of the MIPs. The obtained @MIPs showed monodispersity and the average particle size was around 130 nm. It had a linear fluorescent response within the concentration range 10-100 nmol L^-1 with the correlation coefficient calculated as 0.99625, and the limit of detection was identified as 2.41 nmol L^-1. The results show that Eu(MAA)₃phen as a fluorophore has high luminescent properties, and as a functional monomer, it can improve the selectivity and anti-interference performance of MIPs. Furthermore, the hollow structure made it possible that the imprinted specific recognition sites distributed on both inner and outer surfaces of @MIPs. The experimental results showed that these @MIPs could be employed to the selective detection of chlorophenols under low concentration. And this work will provide a reference for further optimization of fluorescent imprinted sensors.

An overview on molecular imprinted polymers combined with surface-enhanced Raman spectroscopy chemical sensors toward analytical applications

Surface-enhanced Raman spectroscopy (SERS) is a powerful and high-speed detection technology. It provides information on molecular fingerprint recognition with ultrahigh sensitive detection. However, it shows poor anti-interference capacity against complex matrices. Molecularly imprinted polymers (MIPs) can achieve specific recognition of targets from complex matrices. Through introducing the MIP separation system, the MIP-SERS chemical sensor can effectively overcome the limitation of complex matrix interference, and further improve the stability of sensors for detection. Herein, the materials and structures of integrated MIP-SERS sensors are systematically reviewed, and its application as a sensor for chemical detection of hazardous substances in environmental and food samples has been addressed as well. To broaden the prospects of application, we have discussed the current challenges and future perspectives that would accelerate the development of versatile MIP-SERS chemical sensors.

Recent Advances in Molecularly Imprinted Membranes for Sample Treatment and Separation

This review describes the recent advances from the past five years concerning the development and applications of molecularly imprinted membranes (MIMs) in the field of sample treatment and separation processes. After a short introduction, where the importance of these materials is highlighted, a description of key aspects of membrane separation followed by the strategies of preparation of these materials is described. The review continues with several analytical applications of these MIMs for sample preparation as well as for separation purposes covering pharmaceutical, food, and environmental areas. Finally, a discussion focused on possible future directions of these materials in extraction and separation field is also given.

Development of surface imprinted heterogeneous nitrogen-doped magnetic carbon nanotubes as promising materials for protein separation and purification

To promote the development of molecular imprinting technique in the separation and analysis of protein, novel bovine serum albumin (BSA) surface imprinted nitrogen-doped magnetic carbon nanotubes (N-MCNTs@MIPs) are developed by this paper. The imprinted materials are prepared by depositing polydopamine (PDA) on the surface of nitrogen-doped magnetic carbon nanotubes (N-MCNTs). N-MCNTs prepared by high temperature pyrolysis and chemical vapor deposition exhibit high specific surface area, positive hydrophilicity, abundant nitrogen functional groups and excellent magnetic properties. These characteristics are conducive to the increase of effective binding sites, the smooth development of the protein imprinting process in the aqueous phase, the improvement of the binding capacity and the simplification of the separation process. The amount of BSA adsorbing on the N-MCNTs@MIPs can reach 150.86 mg/g within 90 min. The imprinting factor (IF) is 1.43. The results of competitive adsorption and separation of fetal bovine serum showed that N-MCNTs@MIPs can specifically recognize BSA. The excellent reusability and separation ability for real sample prove that N-MCNTs@MIPs have the potential to be applied to the separation and purification of proteins in complex biological samples.

Molecularly imprinted polymer-based electrochemical sensors for environmental analysis

The ever-increasing presence of contaminants in environmental waters is an alarming issue, not only because of their harmful effects in the environment but also because of their risk to human health. Pharmaceuticals and pesticides, among other compounds of daily use, such as personal care products or plasticisers, are being released into water bodies. This release mainly occurs through wastewater since the treatments applied in many wastewater treatment plants are not able to completely remove these substances. Therefore, the analysis of these contaminants is essential but this is difficult due to the great variety of contaminating substances. Facing this analytical challenge, electrochemical sensing based on molecularly imprinted polymers (MIPs) has become an interesting field for environmental monitoring. Benefiting from their superior chemical and physical stability, low-cost production, high selectivity and rapid response, MIPs combined with miniaturized electrochemical transducers offer the possibility to detect target analytes in-situ. In most reports, the construction of these sensors include nanomaterials to improve their analytical characteristics, especially their sensitivity. Moreover, these sensors have been successfully applied in real water samples without the need of laborious pre-treatment steps. This review provides a general overview of electrochemical MIP-based sensors that have been reported for the detection of pharmaceuticals, pesticides, heavy metals and other contaminants in water samples in the past decade. Special attention is given to the construction of the sensors, including different functional monomers, sensing platforms and materials employed to achieve the best sensitivity. Additionally, several parameters, such as the limit of detection, the linear concentration range and the type of water samples that were analysed are compiled.

Molecularly imprinted polyaniline for detection of horseradish peroxidase

A new facile and fast approach to the synthesis of polyaniline (PANi) molecularly imprinted polymers (MIPs) based on aniline oxidative chemical polymerization was proposed for protein recognition. For the first time, a surface imprinting strategy was implemented for the synthesis of PANi MIPs on the inner surface of soft glass polycapillaries (PC) with a large (2237) number of individual microcapillaries. Two different PANi layers-(i) PANi film and (ii) protein imprinted PANi nanowires-were synthesized sequentially. Uniform and highly stable PANi film was synthesized by oxidative polymerization at pH< 1. The synthesis of PANi MIPs on the PANi film pre-coated surface improved the reproducibility of PANi MIP formation. PANi MIP nanowires were synthesized at "mild" conditions (pH > 4.5) to preserve the protein template activity. The binding of horseradish peroxidase (HRP) molecules on the PANi MIP selective sites was confirmed by photometry (TMB chromogenic reaction), SEM images, and FTIR spectroscopy. The developed PANi MIPs enable HRP determination with a limit of detection (LOD) as low as 1.00 and 0.07 ng mL^-1 on the glass slips and PC, respectively. The PANi MIPs are characterized by high stability; they are reversible and selective to HRP. The proposed approach allows PANi MIPs to be obtained for proteins on different supports and to create new materials for separation and sensing. Graphical abstract.

Bacterial Imprinting Methods and Their Applications: An Overview

Microbial contaminations and infections are hazardous and pose crucial concerns for humans. They result in severe morbidity and mortality around the globe. Even though dish-culturing, polymerase chain reaction (PCR), an enzyme-linked immunosorbent assay (ELISA) exhibits accurate and reliable detection of bacteria but these methods are time-consuming, laborious, and expensive. This warrants early detection and quantification of bacteria for timely diagnosis and treatment. Bacteria imprinting ensures a solution for selective and early detection of bacteria by snagging them inside their imprinted cavities. This review provides an insight into MIPs based bacterial detection strategies, challenges, and future perspectives.

Norepinephrine as new functional monomer for molecular imprinting: An applicative study for the optical sensing of cardiac biomarkers

The continuous research for alternatives to antibody-based detection drove, in the last decades, the development of numerous strategies. Molecularly imprinted polymers (MIPs) emerged thanks to the low-cost and long-term stability features, where the choice of natural functional monomer(s) represents the key step for efficient imprinting of biomolecules. The chemical structure of dopamine (DA), one of the most used natural functional monomers, provided the inspiration for this work. We wondered why norepinephrine (NE) that differs from dopamine only for an additional hydroxyl group was not investigated at all in biosensing applications. In fact, there is only one paper exploiting polynorepinephrine (PNE) in molecular recognition applications, taking advantage of molecular imprinting, but not for biosensing purposes. In contrast, hundreds of papers describe polydopamine-based sensors. Therefore, we firstly investigated how the additional hydroxyl group of NE could affect the properties of the resulting polymer, and how these properties could be exploited for biosensing applications. The results highlighted the reduced non-specific adsorption of proteins onto PNE with respect to dopamine polymer. Furthermore, as a case study, we successfully developed a PNE-based imprinted biosensor for the early detection of Troponin I, a crucial biomarker for heart failure, by coupling the MIP biosensor with surface plasmon resonance (SPR) detection. The results indicate the feasible use of imprinted PNE as synthetic receptor for biomolecules, opening new perspectives for this biopolymer, so far not considered, and encouraging further investigations on its potential application in biosensing.

Recent advances in the biosensing of neurotransmitters: material and method overviews towards the biomedical analysis of psychiatric disorders

Neurotransmitters are the most important messengers of the nervous system, and any changes in their balances and activities can cause serious neurological, psychiatric and cognitive disorders such as schizophrenia, Alzheimer's disease and Parkinson's disease.

Molecularly Imprinted Nanoparticles for Biomedical Applications

Molecularly imprinted polymers (MIPs) are synthetic receptors with tailor-made recognition sites for target molecules. Their high affinity and selectivity, excellent stability, easy preparation, and low cost make them promising substitutes to biological receptors in many applications where molecular recognition is important. In particular, spherical MIP nanoparticles (or nanoMIPs) with diameters typically below 200 nm have drawn great attention because of their high surface-area-to-volume ratio, easy removal of templates, rapid binding kinetics, good dispersion and handling ability, undemanding functionalization and surface modification, and their high compatibility with various nanodevices and in vivo biomedical applications. Recent years have witnessed significant progress made in the preparation of advanced functional nanoMIPs, which has eventually led to the rapid expansion of the MIP applications from the traditional separation and catalysis fields to the burgeoning biomedical areas. Here, a comprehensive overview of key recent advances made in the preparation of nanoMIPs and their important biomedical applications (including immunoassays, drug delivery, bioimaging, and biomimetic nanomedicine) is presented. The pros and cons of each synthetic strategy for nanoMIPs and their biomedical applications are discussed and the present challenges and future perspectives of the biomedical applications of nanoMIPs are also highlighted.

Electrochemical molecularly bioimprinted siloxane biosensor on the basis of core/shell silver nanoparticles/EGFR exon 21 L858R point mutant gene/siloxane film for ultra-sensing of Gemcitabine as a lung cancer chemotherapy medication

In search for improvements in bioanalysis electrochemical sensors, for better assessment of anti-cancer drugs, it is necessary for their detection limits to be minimized and the sensitivity and selectivity to be surpassed simultaneously; whereas, resolving any probable interfering with other medical treatments are considered. In this work, a novel approach was adopted for detection and assessment of Gemcitabine (GEM) as an anti-cancer drug based on evaluating its interaction with EGFR exon 21-point mutant gene. An electrochemical nanobiosensor was invented based on a new molecularly bioimprinted siloxane polymer (MBIS) strategy; in which the EGFR exon 21 acts as an identification probe. The roles of multi-walled carbon nanotubes and Ag nanoparticles (NPs) are to perform as a signal amplifier. The MBIS film was prepared by acid-catalysed hydrolysis/condensation of the sample solution, containing Ag NPs, ds-DNA of EGFR exon 21 point mutant gene, GEM as a template molecule, 3-(aminopropyl) trimethoxysilane (APTMS) and tetraethoxysilane. The interaction between the dsDNA and GEM was investigated by employing the modified biosensor and monitoring oxidation signal of guanine and adenine. The produced biosensor was characterized by XRD, FE-SEM, EDS, FT-IR and differential pulse voltammetry. The oxidation signals of adenine and guanine were in linear range when the device was subjected to various concentrations of GEM, from 1.5 to -93 μM, where a low detection limit 12.5 nmol L^-1, and 48.8 nmol L^-1 were recorded by guanine and adenine respectively. The developed biosensor did perform very well when employed for the actual samples; the stability was also approved which was acceptable for a reasonable time.

Molecularly Imprinted Polymer-Based Hybrid Materials for the Development of Optical Sensors

We report on the development of new optical sensors using molecularly imprinted polymers (MIPs) combined with different materials and explore the novel strategies followed in order to overcome some of the limitations found during the last decade in terms of performance. This review pretends to offer a general overview, mainly focused on the last 3 years, on how the new fabrication procedures enable the synthesis of hybrid materials enhancing not only the recognition ability of the polymer but the optical signal. Introduction describes MIPs as biomimetic recognition elements, their properties and applications, emphasizing on each step of the fabrication/recognition procedure. The state of the art is presented and the change in the publication trend between electrochemical and optical sensor devices is thoroughly discussed according to the new fabrication and micro/nano-structuring techniques paving the way for a new generation of MIP-based optical sensors. We want to offer the reader a different perspective based on the materials science in contrast to other overviews. Different substrates for anchoring MIPs are considered and distributed in different sections according to the dimensionality and the nature of the composite, highlighting the synergetic effect obtained as a result of merging both materials to achieve the final goal.

Comparative evaluation of aflatoxin and mineral binding activity of molecular imprinted polymer designed for dummy template using in vitro and in vivo models

The amelioration of aflatoxicosis in ducklings was examined by feeding molecular imprinted polymer (MIP) synthesized to target the aflatoxin B₁ (AFB₁) analog molecule [5, 7-dimethoxycoumarin (DMC)] as a smart and novel toxin binder in comparison to a commercial toxin binder (CTB). MIP was characterized with some techniques, such as scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA) that showed morphology and thermal resistance of MIP, respectively. The SEM showed that more pores and big cavities were formed in the network of the MIP. TGA plots of MIP showed dehydration at temperatures of about 31 °C-200 °C and gradual decomposition until 300 °C. The in vitro and in vivo ability of MIP and CTB to adsorb some minerals (Ca, Cu, Mg, P and Zn) was evaluated. The in vivo efficacy of MIP as an aflatoxins (AFs) binder in duckling exposed to aflatoxin-contaminated feed from 4 to 18 d of age was also compared to that of the CTB. A total of 240 4-d-old ducklings were assigned to experimental diets. Each diet was replicated four times with 10 birds in each pen, and the initial body weight classes were considered as blocks. The experimental treatment diets included: 1- Control (basal diet without any additive or AFs), 2- MIP (5 g/kg diet), 3- CTB (5 g/kg diet), 4- AFs (0.2 mg/kg diet), 5- AFs + MIP (0.2 mg/kg + 5 g/kg diet), and 6- AFs + CTB (0.2 mg/kg + 5 g/kg diet). In vitro study may clearly reflect the possibility of adsorbing minerals by CTB as compared to MIP whilst the results were not confirmed by in vivo study and it seems that reduction in plasma levels of minerals is related to the adverse effects of AFs. Livers showed histopathological alterations, with bile-duct proliferation of all aflatoxin fed ducklings. Macroscopic study indicated liver of birds fed diets containing AFs showed abnormal signs including yellowish, friable and rounded shape without protective effect of MIP and CTB. The results obtained from in vivo study indicate the partial alleviation of the adverse effects of AFs in ducklings by dietary supplementation of MIP and CTB (5 g/kg) on plasma albumin, Zn, Mg and Ca.

Molecularly Imprinted Materials for Selective Biological Recognition

Molecular imprinting is an approach of generating imprinting cavities in polymer structures that are compatible with the target molecules. The cavities have memory for shape and chemical recognition, similar to the recognition mechanism of antigen-antibody in organisms. Their structures are also called biomimetic receptors or synthetic receptors. Owing to the excellent selectivity and unique structural predictability of molecularly imprinted materials (MIMs), practical MIMs have become a rapidly evolving research area providing key factors for understanding separation, recognition, and regenerative properties toward biological small molecules to biomacromolecules, even cell and microorganism. In this review, the characteristics, morphologies, and applicability of currently popular carrier materials for molecular imprinting, especially the fundamental role of hydrogels, porous materials, hierarchical nanoparticles, and 2D materials in the separation and recognition of biological templates are discussed. Moreover, through a series of case studies, emphasis is given on introducing imprinting strategies for biological templates with different molecular scales. In particular, the differences and connections between small molecular imprinting (bulk imprinting, "dummy" template imprinting, etc.), large molecular imprinting (surface imprinting, interfacial imprinting, etc.), and cell imprinting strategies are demonstrated in detail. Finally, future research directions are provided.

Facile preparation of molybdenum carbide (Mo2C) nanoparticles and its effective utilization in electrochemical sensing of folic acid via imprinting

Herein, we propose a facile chemical reduction method to synthesize the molybdenum carbide (Mo₂C) nanoparticles and its application for the electrochemical detection of folic acid (FA) through imprinting technique. Raman scattering, photoelectron spectroscopy and electron microscopy techniques were employed to study the properties of Mo₂C nanoparticles. FA imprinting was carried out in the presence of pyrrole monomer over Mo₂C modified glassy carbon electrode (GCE). The proposed sensor showed the detection behavior for wide range of FA concentrations from 0.01 μM to 120 μM with an excellent LOD value of 4 nM and good selectivity toward FA as compared to other co-existing species in real samples. The fabricated MIP-Mo₂C/GCE sensors were able to be replicated with ∼1.9% RSD, and their reproduced sensor offered good repeatability (RSD; 1.6%) and stability.

A polyhedral oligomeric silsesquioxane/molecular sieve codoped molecularly imprinted polymer for gastroretentive drug-controlled release in vivo

Flotation drug delivery system (FDDS) is recognized as an efficient means to improve the therapeutic efficiency and enhance the drug bioavailability. Herein, we have developed a molecularly imprinted polymer (MIP) against capecitabine (CAP) to fabricate a FDDS by exploiting polyhedral oligomeric silsesquioxane (POSS) and Mobil composition of matter no. 41 (MCM-41) as the codopant. The synergistic effect of POSS and MCM-41 endows MIPs with enhanced imprinting effect and improved mass transfer efficiency. The impacts of the type of dopant, the type of functional monomer, the template/functional monomer ratio and the functional monomer/cross-linker ratio on imprinting effect have been investigated in detail. The POSS/MCM-41 codoped MIPs present favourable sustained release property in vitro and in vivo, displaying a high relative bioavailability of 173.4%. The proposed MIPs with high selectivity and superior physical and chemical stability exhibit potential as an alternative drug carrier applied in FDDS.