Synthesis Of Molecularly Imprinted Polymers Research Articles

Molecularly Imprinted Polymer (MIP) for thiamethoxam: A theoretical and experimental study

The purpose of this work was to study from Density Functional Theory calculations the molecularly imprinted polymer (MIP) for the thiamethoxam (TMX) insecticide. As main results, it was obtained the ideal MIP synthesis protocol as being the methacrylic acid (MAA) as the functional monomer and toluene as the solvent. After the rational design, the material was synthesized and characterized by infrared, thermogravimetric, and scanning electron microscopy analyses. Preliminary adsorption tests have shown that the MIP obtained reached a maximum of equilibrium adsorption in approximately 30 min at pH 7.0, where the insecticide is in molecular form, which favors its extraction.

Synthesis of Molecularly Imprinted Polymers by Two-Step Swelling and Polymerization.

Synthesis of a molecularly imprinted polymer (MIP) by two-step swelling and polymerization is described. Monodisperse, spherical MIP particles, whose diameters are ca. 5-9μm, are prepared using a polystyrene particle as a shape template and dibutyl phthalate as an activating solvent. The obtained MIPs are suitable for separation media in liquid chromatography or solid-phase extraction media. Procedures for synthesis of MIPs and restricted access media (RAM)-MIP, packing of MIPs and RAM-MIPs, and application of MIPs and RAM-MIPs for selective separation and extraction of a target compound(s) are described.

Simple and robust: The claims of protein sensing by molecularly imprinted polymers

Abstract A spectrum of 7562 publications on Molecularly Imprinted Polymers (MIPs) has been presented in literature within the last ten years (Scopus, September 7, 2020). Around 10 % of the papers published on MIPs describe the recognition of proteins. The straightforward synthesis of MIPs is a significant advantage as compared with the preparation of enzymes or antibodies. MIPs have been synthesized from only one up to six functional monomers while proteins are made up of 20 natural amino acids. Furthermore, they can be synthesized against structures of low immunogenicity and allow multi-analyte measurements via multi-target synthesis. Electrochemical methods allow simple polymer synthesis, removal of the template and readout. Among the different sensor configurations electrochemical MIP-sensors provide the broadest spectrum of protein analytes. The sensitivity of MIP-sensors is sufficiently high for biomarkers in the sub-nanomolar region, nevertheless the cross-reactivity of highly abundant proteins in human serum is still a challenge. MIPs for proteins offer innovative tools not only for clinical and environmental analysis, but also for bioimaging, therapy and protein engineering.

Molecularly imprinted polymers in biological applications.

Molecularly imprinted polymers (MIPs) are currently widely used and further developed for biological applications. The MIP synthesis procedure is a key process, and a wide variety of protocols exist. The templates that are used for imprinting vary from the smallest glycosylated glycan structures or even amino acids to whole proteins or bacteria. The low cost, quick preparation, stability and reproducibility have been highlighted as advantages of MIPs. The biological applications utilizing MIPs discussed here include enzyme-linked assays, sensors, in vivo applications, drug delivery, cancer diagnostics and more. Indeed, there are numerous examples of how MIPs can be used as recognition elements similar to natural antibodies.

MIPs for commercial application in low-cost sensors and assays – An overview of the current status quo

Molecularly imprinted polymers (MIPs) have emerged over the past few decades as interesting synthetic alternatives due to their long-term chemical and physical stability and low-cost synthesis procedure. They have been integrated into many sensing platforms and assay formats for the detection of various targets, ranging from small molecules to macromolecular entities such as pathogens and whole cells. Despite the advantages MIPs have over natural receptors in terms of commercialization, the striking success stories of biosensor applications such as the glucose meter or the self-test for pregnancy have not been matched by MIP-based sensor or detection kits yet. In this review, we zoom in on the commercial potential of MIP technology and aim to summarize the latest developments in their commercialization and integration into sensors and assays with high commercial potential. We will also analyze which bottlenecks are inflicting with commercialization and how recent advances in commercial MIP synthesis could overcome these obstacles in order for MIPs to truly achieve their commercial potential in the near future.

Molecularly imprinted polymers for selective extraction of rosmarinic acid from Rosmarinus officinalis L.

This study provides a robust and reproducible approach for selective extraction of rosmarinic acid (RA) using molecularly imprinted polymers (MIPs). Computational modeling and UV spectroscopic analysis were performed to optimize MIP synthesis. Consequently, six different bulk and surface imprinted polymers were generated using RA as the template. Binding performance of the imprinted polymers was evaluated using static equilibrium and complementary dynamic rebinding experiments. Despite the high selectivity of thus generated surface imprinted polymers, the corresponding bulk polymers exhibited better binding performance when serving as sorbents during solid phase extraction (SPE). An optimized molecularly imprinted solid phase extraction (MISPE) protocol was developed in respect to loaded amount of RA, composition of the loading solution, washing solvent, and elution volume. Thereby, a remarkably selective extraction of RA from real-world Rosmarinus officinalis L. extract with a recovery rate and purity of 81.96 ± 6.33% and 80.59 ± 0.30%, respectively, was achieved.

Microsphere Polymers in Molecular Imprinting: Current and Future Perspectives.

Molecularly imprinted polymers (MIPs) are specific crosslinked polymers that exhibit binding sites for template molecules. MIPs have been developed in various application areas of biology and chemistry; however, MIPs have some problems, including an irregular material shape. In recent years, studies have been conducted to overcome this drawback, with the synthesis of uniform microsphere MIPs or molecularly imprinted microspheres (MIMs). The polymer microsphere is limited to a minimum size of 5 nm and a molecular weight of 10,000 Da. This review describes the methods used to produce MIMs, such as precipitation polymerisation, controlled/‘Living’ radical precipitation polymerisation (CRPP), Pickering emulsion polymerisation and suspension polymerisation. In addition, some green chemistry aspects and future perspectives will also be given.

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 0.07ngmL-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.

Electroactive Molecularly Imprinted Polymer for Selective Detection of 4-Nitrophenol

We propose to develop a reusable electro-chemical sensor for selective detection of 4-nitrophenol (4-NP), based on molecularly imprinted polymer (MIP) technology. MIP technology is the design of an artificial receptor with high selectivity for a specific analyte. Our approach combines N-isopropylacrylamide (NIPAM) backbone polymer with different functional monomers to improve the selectivity and sensitivity of 4-nitrophenol (4-NP) detection.The key points of our sensor polymer are:1) reduced amount of covalent crosslinker methylene bis-acrylamide (MBA) to increase rebinding kinetics and affinity and 2) modified polymer backbone with an electroactive block deposited on a gold surface. To get rapid high affinity template rebinding, we used a reduced amount of covalent crosslinker and used noncovalent crosslinking based on acid-base and hydrophobic interactions. To form acid-base crosslinking, we used 4-vinylpyridine (4-VP) as the basic monomer and methacrylic acid (MAA) as acidic monomer.In MIPs synthesis part, our strategy takes the advantage of reversible addition fragmentation-chain transfer (RAFT) polymerization to control the polymer chain length and modify the terminus as poly-ferrocene methyl methacrylate (FMMA), an electroactive block. The RAFT agent contains R group and Z group which are at different ends of polymer. The Z side is reduced to a thiol and deposited on gold. The PolyFMMA block is on the R side. RAFT agent, FMMA monomers and initiator were added to a batch system to synthesis the first electroactive block. Then, all chemicals including backbone monomers, functional monomers, crosslinkers and templates (4-NP) were added to form the major polymer block. After synthesis, templated-MIPs were dialyzed to remove the template for further target selective detection.One of the major challenges of our sensor is polymer tangling which affect measurement stability. To reduce polymer tangling effects, we dissolved the template-removed MIPs into tetrahydrofuran (THF) and controlled the gold electrode surface coverage. We deposited MIPs on an additional flat gold chip and used atomic force microscope (AFM) to characterize the surface coverage distribution.The modified gold electrode can be used in electrical impedance spectroscopy (EIS) or cyclic voltammetry (CV) to measure charge transfer distance before and after template rebinding to detect unknown concentration target analytes.

Synthesis and characterization of stigmasterol imprinted polymers with precipitation polymerization method

Molecularly imprinted polymers (MIP) are porous materials that have an active binding site and can recognize specific target molecules. MIP synthesis was carried out by precipitation polymerization method using toluene as a porogen solvent and stigmasterol molecule as a template molecule. The synthesized NIP and MIP were characterized using FTIR and SEM-EDS. The ability of MIP adsorption on Stigmasterol was determined by concentration measurements using UV-Vis. The results of the characterization using FTIR showed that the functional groups that influence the formation of NIP and MIP are -OH, -CH, C=C, and -C=O. Characterization using SEM shows that the surface morphology of MIP is rougher than NIP. Characterization using EDS showed that there was a decrease in mass% by 2.54% and C% atom by 2.08% in MIP after extracting the Stigmasterol molecule. The ability of MIP adsorption on stigmasterol was 0.204 mg/g, while the ability of NIP adsorption on stigmasterol was 0.040 mg / g. The ability of MIP adsorption to stigmasterol molecules is better than NIP. Therefore, MIP can be used as an adsorbent to adsorb stigmasterol in sample extracts.

Pre-concentration of rosuvastatin using solid-phase extraction in a molecularly imprinted polymer and analytical application in water supply

In this work, it is shown the development and validation of innovative analytical methodology based on solid-phase extraction (SPE) with molecularly imprinted polymers (MIP) as a sorbent associated to UV-Vis spectroscopy to isolate and quantify, respectively, rosuvastatin (RSV) in water samples. For this purpose, porogenic solvent in MIP synthesis and SPE extraction parameters for MIP and non-imprinted polymers (NIP) were evaluated univariately for comparison purposes. The sorptive capacity and characterization studies by infrared spectroscopy and atomic force microscopy showed difference between MIP and NIP. The selectivity study of the MIP-RSV against other statins (simvastatin and atorvastatin) showed that the synthesized MIP can also be applied as a solid phase for isolation and quantitative pre-concentration of RSV and atorvastatin. The conjugation of SPE and UV-Vis spectroscopy in the determination of RSV in aqueous matrices led to large factor of pre-concentration (125 times), limit of detection (LOD) of 3μgL-1, limit of quantification (LOQ) of 10μgL-1, precision of 2.87% (n = 10), and accuracy of 83.1% (n = 4).

Molecularly imprinted polymer solid-phase extraction for the analysis of 1,8-cineole in thyme and sagebrush distillates

Molecularly imprinted polymers (MIPs) are polymers possessing receptor cavities with selective characteristics. The molecularly imprinted polymer of 1,8-cineole on hydroxyl-functionalized multiwall carbon nanotubes was synthesized for selective extraction of 1,8-cineole in water distillates of Artemisia sieberi (sagebrush) and thyme samples. The MIP was synthesized with cineole as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker and benzoyl peroxide as initiator. The main parameters affecting the synthesis of MIP and also the extraction efficiency of the analyte were optimized. The limit of detection of 1,8-cineole was as low as 0.04 μg/mL, while the dynamic linear range was found to be in the range of 0.125–100 µg/mL. The relative standard deviations (RSDs%) found for samples spiked at 1 and 70 µg/mL were 1.45–4.3%, respectively. The relative recoveries of the spiked samples at the above concentration levels were 93.8–98.2%.

Evaluation of Molecularly Imprinted Polymers for Point-of-Care Testing for Cardiovascular Disease.

Molecular imprinting is a rapidly growing area of interest involving the synthesis of artificial recognition elements that enable the separation of analyte from a sample matrix and its determination. Traditionally, this approach can be successfully applied to small analyte (<1.5 kDa) separation/ extraction, but, more recently it is finding utility in biomimetic sensors. These sensors consist of a recognition element and a transducer similar to their biosensor counterparts, however, the fundamental distinction is that biomimetic sensors employ an artificial recognition element. Molecularly imprinted polymers (MIPs) employed as the recognition elements in biomimetic sensors contain binding sites complementary in shape and functionality to their target analyte. Despite the growing interest in molecularly imprinting techniques, the commercial adoption of this technology is yet to be widely realised for blood sample analysis. This review aims to assess the applicability of this technology for the point-of-care testing (POCT) of cardiovascular disease-related biomarkers. More specifically, molecular imprinting is critically evaluated with respect to the detection of cardiac biomarkers indicative of acute coronary syndrome (ACS), such as the cardiac troponins (cTns). The challenges associated with the synthesis of MIPs for protein detection are outlined, in addition to enhancement techniques that ultimately improve the analytical performance of biomimetic sensors. The mechanism of detection employed to convert the analyte concentration into a measurable signal in biomimetic sensors will be discussed. Furthermore, the analytical performance of these sensors will be compared with biosensors and their potential implementation within clinical settings will be considered. In addition, the most suitable application of these sensors for cardiovascular assessment will be presented.

Preparation of Molecularly Imprinted Magnetic Graphene Oxide-Gold Nanocomposite and Its Application to the Design of Electrochemical Sensor for Determination of Epinephrine

In this study, a new molecularly imprinted polymer (MIP) based nanocomposite was synthesized then used to determine epinephrine (EPN) by the use of an electrochemical sensor modified by it. Typical techniques for the synthesis of MIP have disadvantages, such as weak binding sites, low mass transfer and low selectivity. One of the ways to improve electrochemical properties is the use of graphene oxide (GR-Ox) and modification of its surface. For this purpose, GR-Ox was initially magnetized (MGR-Ox), then its surface was coated with a silica layer, and gold nanoparticles (AuNPs) were coated on its surface. Subsequently, copolymerization of methacrylic acid (MAA) and N,N'-methylene-bis-acrylamide (MBA) in the presence of EPN was performed on the MGO-AuNPs surface. Afterwards, a selective carbon paste electrode (CPE) with synthetic nanocomposite was fabricated to detect EPN. Under optimal conditions, a linear range from 10-8 to 5.0 × 10-7 M was obtained for the measurement of EPN in urine and blood with a detection limit of 5 × 10-9 M (S/N = 3).

Development of a molecularly imprinted monolithic polymer disk for agitation-extraction of ecgonine methyl ester from environmental water

In this study, a new extraction approach based on rotating molecularly imprinted polymer (MIP) disks was developed. The preparation procedure of MIP-disk is simple. Firstly, in order to immobilize MIP onto the surface of polytetrafluoroethylene (PTFE) disk, previous modification and vinylization steps of this fluoropolymer were conducted. Then, MIP synthesis was done by in situ polymerization. The resulting MIP was characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Afterwards, two ring magnets were placed in the sides of the MIP-disk to integrate the stirring and preconcentration of sample in just one step. To demonstrate the feasibility of this novel extraction system, the selective extraction of ecgonine methyl ester (EME) from water samples was performed. Extraction conditions were also evaluated and the extracts were analyzed by ion mobility spectrometry and by ultrahigh performance liquid chromatography-tandem mass spectrometry, allowing limits of detection of 13 and 75 ng L−1, respectively. Field surface water and wastewater were analyzed using the proposed methodology, being a good alternative for the fast and potentially portable methodology for in-field screening analysis.

Dopamine-based molecularly imprinted polymers for the recognition of biomacromolecules

Compared to natural antibodies or receptors, molecularly imprinted polymers (MIPs) have shown advantages of easy preparation, low cost, high stability and reusability. MIPs have been widely used in the fields of separation, chemical sensing, drug delivery and biocatalysis. The development of new imprinting methods such as surface imprinting, epitope imprinting, post-imprinting modification have promoted the synthesis and application of MIPs against biomacromolecules. Despite of the success, it remains a challenge to prepare MIPs with high affinity and specificity to the target proteins because the options of water-soluble monomers are very limited and the protein’s conformation is liable to change during the polymerization reaction. The majority of protein imprinting studies employ the five most common monomers: acrylamide (AAm), methacrylic acid (MAA), aminophenylboronic acid (APBA), acrylic acid (AA), and N-isopropylacrylamide (NiPAAm) and the two frequently used crosslinkers, methylenebisacrylamide (MBA) and ethylene glycol dimethacrylate (EGDMA) for preparation of protein imprinted polymers. In recent years, dopamine (DA) has been frequently used for surface modification as it can self-polymerize in alkaline medium at room temperature and generate polydopamine (pDA) films that can adhere onto almost all inorganic and organic surfaces with good biocompatibility. Thus, DA emerged as an appropriate monomer as well as a crosslinker for various imprinting reactions. In this review, we highlighted the recent advances in design and fabrication of DA-based MIPs for various biomacromolecules, including proteins, glycoproteins, bacteria or virus, with focus on protein imprinted polymers. First, we briefly introduced the DA self-polymerization reaction and the reported mechanisms for pDA formation. It is generally accepted that the initial driving force for the formation of pDA is the oxidation of DA to DA-indole by dissolved oxygen in an alkaline solution. Then, we summarized the recent work that employs common protein such as human/bovine serum albumin (HSA/BSA), lysozyme (Lyz), hemoglobin, trypsin and immunoglobulin (IgG) as the imprinting templates. These MIPs were mainly used for separation and purification of the template proteins. We also introduced the combination of protein imprinting with quartz crystal microbalance (QCM), cyclic voltammetry (CV), surface plasmon resonance (SPR) and mass spectroscopy (MS) for recognition and detection of the target proteins. In the following part, we summarized the strategies developed for imprinting of glycoproteins, most of which took advantage of boron affinity reaction or lectin-sugar interaction to improve the affinity and selectivity of the resultant MIPs. Then, we introduced recent work on imprinting of microorganisms such as viruses and bacteria, in which surface imprinting technique and potential analysis or chemiluminescence (ECL) technique are combined to construct biosensors that can selectively detect target species with high sensitivity. In addition, we also introduced the synthesis of a bio-inspired virus imprinted polymer and its application for prevention of viral infections. The techniques which were used for characterizing the properties of the MIP materials, e.g., adsorption capacity, imprinting factor and selectivity, as well as the proposed theoretical model were also mentioned in the review. Finally, we discussed current challenges and possible solutions for using DA as a monomer to prepare MIPs for biomacromolecules. We believe that the interactions between the intermediate products during dopamine polymerization and the template proteins deserve further investigation, as it may provide more possibilities to modulate the binding properties of the obtained MIPs.

Molecularly imprinted polymer for selective adsorption of diclofenac from contaminated water

The presence of pharmaceuticals, such as non-steroidal anti-inflammatory drugs (NSAIDs) in the aquatic environment represents a worldwide threat. NSAIDs are considered “emerging contaminants” of water since the traditional methods are not designed to efficiently remove them. Aiming to overcome the limits of the conventional wastewater treatment plants, we propose molecularly imprinted polymers (MIPs) as valid tools for selective adsorption and removal of these drugs from water. In particular, in this work, we have prepared diclofenac-selective MIP by a simple bulk polymerization process. After the characterization of the synthetized polymers, the binding abilities were evaluated in detail through the adsorption of diclofenac in aqueous solution and compared with the abilities of a corresponding non-imprinted polymer used as a reference. Thanks to the imprinting effect, the prepared MIP adsorbs with extreme selectivity its template molecule, i.e. the diclofenac. This effect was evaluated by testing the adsorption abilities towards different drugs, such as acetylsalicylic acid and trimethoprim. In addition, MIP reusability was demonstrated after a simple regeneration step. The strength of this work is due to the low cost synthesis of MIP and to its optimal performance of molecular recognition in water, differentially from many of the traditional MIPs, usually used with organic solvent. Such peculiarities make the material potentially applicable for water treatment on a large scale.

Aflatoxins screening in non-dairy beverages by Mn-doped ZnS quantum dots – Molecularly imprinted polymer fluorescent probe

Synthesized molecularly imprinted polymer (MIP) materials have been anchored on the surface of PEG-Mn-doped ZnS quantum dots (QDs) to develop a fluorescence probe for aflatoxins (AFs) recognition/determination in non-dairy beverages. MIP synthesis used 5,7-dimethoxycoumarin (DMC) as a dummy template molecule, and methacrylic acid (MAA) as a functional monomer. Under optimized conditions (1.25 mL of 5 mg L−1 MIP-PEG-ZnS QDs solution, pH 5.0, and 12 min delay time before scanning), the prepared MIP-QDs composite was found to offer high affinity and selectivity for AFs (AFB1, AFB2, AFG1 and AFG2). A fast fluorimetric screening method (total AFs assessment) was therefore feasible. The limits of detection (LOD) and quantification (LOQ) were 0.016 and 0.053 mg L−1, respectively. Analytical recoveries (inter- and intra-day assays) were from 99 ± 4% to 107 ± 5%, with RSD (intra-day assay) lower than 13, and RSD (inter-day) lower than 7%. The optimized method was applied for total AFs assessment in several non-dairy beverage samples.

Pickering emulsion-based molecular imprinting

Due to the specific recognition ability of the target molecules, molecularly imprinted polymers (MIPs) have been widely used in many fields. So far, the research in molecular imprinting mainly focused on two aspects: (1) synthesis of MIPs with more functions; (2) expanding applications of the traditional MIPs, especially for MIPs synthesized by precipitation polymerization. To address these points, our group recently introduced a new insight in molecular imprinting based on Pickering emulsion: (1) Pickering emulsion polymerization could be used to the synthesize water-compatible MIP spheres with well-controlled structures; (2) MIP nano/microparticles stabilized emulsions were introduced to molecular imprinting to endow the MIP particles with more functions, or to create new interfacial binding or catalytic systems for MIP nano/microparticles. It is noted that, although the first molecular imprinting in Pickering emulsion has been presented for only a few years, the publications in this field increased very fast. In this review, we summarized the synthesis of MIP spheres via Pickering emulsion polymerization, and discussed the advantages and limitations of this synthesis method. Due to the unique properties of the particle stabilized emulsion, the imprinted systems offered several advantages to the resulted MIP spheres, and which could be further utilized to solve the long-tern challenges in imprinting of small molecules: (1) well-designed hierarchical structures (surface nano-pores from the particle stabilizers and accessible molecular binding cavities from the templates); (2) group recognition of a series of chemicals with a similar moiety (epitope imprinting); and (3) specific recognition capability in aqueous conditions because of the hydrophilic surface of the MIPs. Moreover, for imprinting biomacromolecules and other large templates (virus particles, bacteria and animal cells), Pickering emulsion was also particularly interesting, because the templates themselves could be directly used as solid stabilizers to synthesis Pickering emulsion, and thus created accessible surface imprinted sites for the recognition. In this review, we also demonstrated that MIP nano/microparticles stabilized emulsions were promising interfacial systems in molecular imprinting. On one hand, this emulsion could be utilized for the fabrication of functional materials with pre-designed recognition ability towards the target molecules. As examples, the Janus MIP particles, which displayed attractive abilities as self-propelled transporters for controlled drug delivery, could be prepared via a wax-water Pickering emulsion. Multifunctional colloidosomes, which showed both specific molecular recognition of the MIP nanoparticles and dose-dependent fluorescence response to fructose, could be synthesized by using W/O Pickering emulsions stabilized by clickable nanoparticles: Alkyne-coated MIP nanoparticles and azide-modified nanoparticles, followed by an interfacial click reaction. On the other hand, the introduction of Pickering emulsion expanded tha application environment of the traditional MIP nano/microparticles to a oil-water interface. For example, MIP microgel stabilized Pickering emulsions with the capability to catalyze the formation of disulfide bonds in peptides at the O/W interface has been reported recently. These works system will greatly promote the application of molecular imprinting in various fields such as organic synthesis, disease diagnosis, proteomics and bio-imaging Moreover, we discussed the prospects of the applications of molecular imprinting in Pickering emulsion in a near future, (1) uniform MIP spheres should be fabricated by optimizing the emulsion systems and choosing suitable reactors; (2) stable Pickering emulsion systems should be developed for biomacromolecular imprinting, such as proteins, micro organisms and human cells; (3) MIP nano/microparticles prepared by Pickering emulsion should be designed for immunoassay, biomedicine, environmental governance and chemical catalysis. As a summary, we believed that molecular imprinting in Pickering emulsion provided a facile synthetic approach for producing new functional materials, as well as an interfacial binding or catalytic environment for appilication of the traditional MIP nano/microparticles. All these works show great potential in clinical pathogenic screening, noninvasive detection and drug delivery.

Influence of synthesis conditions on the production of molecularly imprinted polymers for the selective recovery of isovaleric acid from anaerobic effluents

AbstractTwo molecularly imprinted polymers (MIPs) – poly(methacrylic acid‐co‐TRIM) (TRIM, trimethylolpropanetrimethacrylate) and poly(acylamide‐co‐TRIM) – were synthesized in different solvents for the selective recovery of isovaleric acid (template) generated during the anaerobic digestion process. The chemical and structural characterizations of the synthetic adsorbent were carried out by Fourier transform infrared spectroscopy, TGA and porosimetry through N2 adsorption–desorption isotherms. The selective and adsorptive performances of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic and selectivity studies and by adsorbent reuse experiments. The poly(methacrylic acid‐co‐TRIM) synthesized with dimethyl sulfoxide:chloroform presented higher selectivity and adsorption capacity for isovaleric acid in the presence of six volatile fatty acids. The kinetic results were well adjusted to the pseudo‐nth order and intraparticle diffusion models, leading to k values of 10−4 and 6 × 10−5 for the best synthesis of MIPs and not‐imprinted polymers, respectively. Moreover, the Sips model best described the adsorption isotherm and generated a maximum adsorption capacity of ca 209 mg g−1 (at 25 °C). Cycles of MIP use–desorption–reuse indicated that the selective adsorbent performed better than commercial adsorbents, losing less than 3% of adsorption capacity after three cycles. © 2018 Society of Chemical Industry