Novel oligo(ethylene glycol)-based molecularly imprinted magnetic nanoparticles for thermally modulated capture and release of lysozyme

Milk protein hydrolysates obtained with immobilized alcalase and neutrase on magnetite nanoparticles: Characterization and antigenicity study

Enzymatic hydrolysis is the most commonly used method to reduce the antigenicity of milk protein, but free protease is unstable and difficult to recycle after application. In this study, alcalase and neutrase were selected for immobilization on the modified magnetic Fe₃ O₄ nanoparticles. The reusability of the immobilized enzyme was 68.23% of the total starting activity after 5 recycling batches. The optimal hydrolysis conditions were an enzyme to substrate ratio of 6000 U/g and reaction at 50℃ and pH 8.5 for 3 h. Under these conditions, 22.76% hydrolysis of hydrolysate was achieved, and the antigenicity reduction rates of β-lactoglobulin and casein were 21.34% and 30.89%, respectively. In addition, 82.75% of the hydrolysate had a molecular weight less than 1 kDa, and free amino acids represented 13.65% of the sample. This result showed that the hydrolysis with immobilized enzyme was similar to that with free enzyme and the immobilized enzyme could be applied to produce hypoallergenic hydrolysate. PRACTICAL APPLICATION: Reduces milk protein allergenicity.

Application progress of magnetic molecularly imprinted polymers chemical sensors in the detection of biomarkers

Specific recognition and highly sensitive detection of biomarkers play an essential role in identification, early diagnosis and prevention of many diseases. Magnetic molecularly imprinted polymers (MMIPs) have been widely used to capture biomimetic receptors for targets in various complex matrices due to their superior recognition ability, structural stability, and rapid separation characteristics, which overcome the existing deficiencies of traditional recognition elements such as antibodies, aptamers. The integration of MMIPs as recognition elements with chemical sensors opens new opportunities for the development of advanced analytical devices with improved selectivity and sensitivity, shorter analysis time, and lower cost. Recently, MMIPs-chemical sensors (MMIPs-CS) have made significant progress in detection, but many challenges and development spaces remain. Therefore, this review focuses on the research progress of the sensor based on biomarker detection and introduces the surface modification of the magnetic support material used to prepare high selective MMIPs, as well as the selective extraction of target biomarkers by MMIPs from the complex biological sample matrix. Based on the understanding of optical sensors and electrochemical sensors, the applications of MMIPs-optical sensors (MMIPs-OS) and MMIPs-electrochemical sensors (MMIPs-ECS) for biomarker detection were reviewed and discussed in detail. Moreover, it provides an overview of the challenges in this research area and the potential strategies for the rational design of high-performance MMIPs-CS, accelerating the development of multifunctional MMIPs-CS.

Temperature-Responsive Magnetic Nanoparticles for Bioanalysis of Lysozyme in Urine Samples

Highly selective multifunctional magnetic nanoparticles containing a thermoresponsive polymer shell were developed and used in the sample pretreatment of urine for the assessment of lysozymuria in leukemia patients. Crosslinked poly(N-isopropylacrylamide-co-acrylic acid-co-N-tert-butylacrylamide) was grown onto silica-coated magnetic nanoparticles by reversible addition fragmentation chain transfer (RAFT) polymerization. The lysozyme binding property of the nanoparticles was investigated as a function of time, protein concentration, pH, ionic strength and temperature and their selectivity was assessed against other proteins. High-abundant proteins, like human serum albumin and γ-globulins did not interfere with the binding of lysozyme even at elevated concentrations characteristic of proteinuria. A sample cleanup procedure for urine samples has been developed utilizing the thermocontrollable protein binding ability of the nanoparticles. Method validation was carried out according to current bioanalytical method validation guidelines. The method was highly selective, and the calibration was linear in the 25 to 1000 µg/mL concentration range, relevant in the diagnosis of monocytic and myelomonocytic leukemia. Intra- and inter-day precision values ranged from 2.24 to 8.20% and 1.08 to 5.04%, respectively. Intra-day accuracies were between 89.9 and 117.6%, while inter-day accuracies were in the 88.8 to 111.0% range. The average recovery was 94.1 ± 8.1%. Analysis of unknown urine samples in comparison with a well-established reference method revealed very good correlation between the results, indicating that the new nanoparticle-based method has high potential in the diagnosis of lysozymuria.

Immobilization of glyceraldehyde-3-phosphate dehydrogenase on Fe3O4 magnetic nanoparticles and its application in histamine removal

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Lactobacillus plantarum is a novel biocatalyst in the degradation of histamine, but its properties need enhancement before practical application. Herein, we used Fe₃O₄ magnetic nanoparticles (MNPs) as the carrier core to prepare immobilized GAPDH. GAPDH was cloned, expressed in E. coli and purified, followed by immobilization on Fe₃O₄ MNPs and characterization by TEM and FT-IR. Then, characteristic comparisons between immobilized enzyme and its free form showed that the optimal pH and temperature of the former shifted to 7.5 and 40 °C, respectively, and pH tolerance and thermostability were separately broadened to 4.5-8.5 and 50-60 °C. In a wine-making experiment, including grape and black raspberry wines, using the immobilized enzyme, the results showed that over 81 %, 75 % and 59 % of histamine was removed after each treatment. These findings demonstrate that immobilizing GAPDH onto Fe₃O₄ MNPs is facile and efficient for histamine removal in fermented beverages.

Molecularly Imprinted Polyscopoletin for the Electrochemical Detection of the Chronic Disease Marker Lysozyme

Herein we report the electropolymerization of a scopoletin based molecularly imprinted polymer (MIP) for the detection of lysozyme (Lyz), an enzymatic marker of several diseases in mammalian species. Two different approaches have been used for the imprinting of lysozyme based, respectively, on the use of a monomer-template mixture and on the covalent immobilization of the enzyme prior to polymer synthesis. In the latter case, a multi-step protocol has been exploited with preliminary functionalization of gold electrode with amino groups, via 4-aminothiophenol, followed by reaction with glutaraldehyde, to provide a suitable linker for lysozyme. Each step of surface electrode modification has been followed by cyclic voltammetry and electrochemical impedance spectroscopy, which has been also employed to test the electrochemical responses of the developed MIP. The sensors show good selectivity to Lyz and detect the enzyme at concentrations up to 292 mg/L (20 μM), but with different performances, depending on the used imprinting approach. An imprinting factor equal to 7.1 and 2.5 and a limit of detection of 0.9 mg/L (62 nM) and 2.1 mg/L (141 nM) have been estimated for MIPs prepared with and without enzyme immobilization, respectively. Competitive rebinding experiment results show that this sensing material is selective for Lyz determination. Tests were performed using synthetic saliva to evaluate the potential application of the sensors in real matrices for clinical purposes.

Application of stimuli-responsive materials for extraction purposes

Stimuli-responsive materials, frequently designated as "smart/intelligent materials", can modify their structure or properties by either a biological, physical, or chemical stimulus which, if properly controlled, could be used for specific applications. Such materials have been studied and exploited in several fields, like electronics, photonics, controlled drugs administration, imaging and medical diagnosis, among others, as well as in Analytical Chemistry where they have been used as chromatographic stationary phases, as part of sensors and for extraction purposes. This review article pretends to provide an overview of the most recent applications of these materials (mostly polymeric materials) in sample preparation for extraction purposes, as well as to provide a general vision of the current state-of-the-art of this field, their potential use and future applications.

Design of Functional Magnetic Nanocomposites for Bioseparation

Magnetic materials have been widely used in bioseparation in recent years due to their good biocompatibility, magnetic properties, and high binding capacity. In this review, we provide a brief introduction on the preparation and bioseparation applications of magnetic materials including the synthesis and surface modification of magnetic nanoparticles as well as the preparation and applications of magnetic nanocomposites in the separation of proteins, peptides, cells, exosomes and blood. The current limitations and remaining challenges in the fabrication process of magnetic materials for bioseparation will be also detailed.

Reduction-responsive molecularly imprinted nanogels for drug delivery applications

Degradable molecularly imprinted polymers (MIPs) with affinity for S-propranolol were prepared by the copolymerization of methacrylic acid as functional monomer and a disulfide-containing cross-linker, bis(2-methacryloyloxyethyl)disulfide (DSDMA), using bulk polymerization or high dilution polymerization for nanogels synthesis. The specificity and the selectivity of DSDMA-based molecularly imprinted polymers toward S-propranolol were studied in batch binding experiments, and their binding properties were compared to a traditional ethylene glycol dimethacrylate (EDMA)-based MIP. Nanosized MIPs prepared with DSDMA as crosslinker could be degraded into lower molecular weight linear polymers by cleaving the disulfide bonds and thus reversing cross-linking using different reducing agents (NaBH4, DTT, GSH). Turbidity, viscosity, polymer size and IR-spectra were measured to study the polymer degradation. The loss of specific recognition and binding capacity of S-propranolol was also observed after MIP degradation. This phenomenon was applied to modulate the release properties of the MIP. In presence of GSH at its intracellular concentration, the S-propranolol release was higher, showing that these materials could potentially be applied as intracellular controlled drug delivery system.

Controlled synthesis of PEGylated surface protein-imprinted nanoparticles

High recognition selectivity has been the main object in developing protein-imprinted materials. Here, we demonstrate a novel strategy for the controlled synthesis of PEGylated surface protein-imprinted nanoparticles with reduced nonspecific binding, which is based on sequential two steps of surface-initiated reversible addition-fragmentation chain transfer aqueous precipitation polymerization (SI-RAFT APP). Click chemistry was employed to construct hydrophilic nanocores with both high-density RAFT chain transfer agents and template-capturing groups. Through the first-step SI-RAFT APP, protein-imprinted nanoshells were formed over the nanocores using lysozyme as a model template. By the second-step SI-RAFT APP, nonlinear PEG chains were grafted from the core-shell imprinted nanoparticles before the removal of the template. Both the thickness of the imprinted nanoshells and the length of the grafted chains could be readily controlled by the polymerization time. Thus the obtained PEGylated core-shell particles exhibited greatly improved template binding selectivity compared with the non-PEGylated controls, typically with the imprinting factor increasing from 2.1 to 9.1. Meanwhile, the PEGylation process did not impair but significantly enhance the protein binding capacity. The generality of the established approach was preliminarily proved by imprinting another template protein, bovine hemoglobin. This work represents the first example for the controlled synthesis and post-imprinting functionalization of surface protein-imprinted nanoparticles via SI-RAFT polymerization.

Self-Assembled Regenerated Silk Fibroin Microsphere-Embedded Fe3O4 Magnetic Nanoparticles for Immobilization of Zymolyase

Cytoplasm of Saccharomyces cerevisiae yeast cells contains a significant amount of desired intracellular products for both industrial utility and academic research. To recover intracellular compounds, it is necessary to break the yeast cells with high efficiency, which, under certain circumstances, requires the use of the lytic enzyme zymolyase to completely digest the cell walls. A promising strategy for zymolyase immobilization on silk fibroin (SF) was developed. SF/Fe3O4 magnetic microspheres (MMs) were constructed by solvent (ethanol)-induced self-assembly of SF surrounding Fe3O4 magnetic nanoparticles (MNs), which were synthesized by a coprecipitation method. Zymolyase was covalently bonded on the surface of the SF/Fe3O4 MMs by a photochemical cross-linking method to produce robust biocatalysts of zymolyase/SF/Fe3O4. The chemical, magnetic, and morphological properties of the MM supports and the immobilized zymolyase were investigated. Enzymolysis results demonstrated that the immobilized zymolyase showed good activity and stability for digesting yeast cell walls, and the biocatalyst can be readily recycled through convenient magnetic separation for reuse. At the optimum pH = 7.5, the immobilized zymolyase maintained 84% of the activity of the free zymolyase and retained 41% of its initial activity after four times of reuse. At unfavorable acidic pH = 4, the immobilized zymolyase retained 81% of its initial activity, while the free zymolyase showed no significant activity. Consequently, the SF/Fe3O4 MMs exhibit superior performance in terms of immobilizing enzymes, which have a good prospect in the biological application.

Thermoregulated extraction of luteolin under neutral conditions using oligo(ethylene glycol)-based magnetic nanoparticles with Wulff-type boronate affinity

Oligo(ethylene glycol)-based thermoresponsive polymers with Wulff-type boronate affinity were anchored on magnetic nanoparticles. The resultant magnetic nanoparticles were used as sorbents for extracting luteolin, a cis-diol-containing model analyte. By exploiting the thermoresponsive properties and Wulff-type boronate affinity of the sorbents, target adsorption at room temperature (25 °C) and target release at high temperature (40 °C) were achieved under neutral conditions without pH alteration. The proposed thermoregulated extraction method was favorable for automated boronate affinity extraction, preventing degradation of the target and avoiding acidic elution for breaking Wulff-type boronate sites. Compared to reported sorbents for extracting luteolin, the sorbents possessed higher maximum adsorption capacity (98.7 mg g^-1) with acceptable sensitivity, simplified operation procedure, and mild extraction condition. Furthermore, the sorbents were applied in thermoregulated extraction of luteolin from honey samples. Satisfactory recoveries in the range of 83.2% - 89.1% with RSD ranging from 2.2% to 4.6% were achieved. The results demonstrated that this work provided a new research direction to design and synthesize efficient thermoresponsive materials for recognition and release of cis-diol compounds under neutral conditions.

Thermo-Responsive Molecularly Imprinted Hydrogels for Selective Adsorption and Controlled Release of Phenol From Aqueous Solution

In this study, thermo-responsive molecularly imprinted hydrogels (T-MIHs) were developed as an effective potential adsorbent for selectively adsorption phenol from wastewater. During the process, N-isopropyl acrylamide (NIPAm) was used as thermal responsive monomer. The obtained materials were characterized in detail by fourier transform infrared (FT-IR) spectrometer, scanning electron microscope (SEM), and thermo gravimetric analysis (TGA). A series of static adsorption studies were performed to investigate the kinetics, specific adsorption equilibrium, and selective recognition ability of phenol. Reversible adsorption and release of phenol were realized by changing temperatures. Three type of phenols, namely 3-chlorophenols (3-CP), 2,4-dichlorophenol (2,4-DCP), and 2,4,6-trichlorophenol (2,4,6-TCP) were selected as model analytes to evaluate the selective recognition performance of T-MIHs. The T-MIHs have good selectivity, temperature response, and reusability, making them ideal in applying in the controlled separation and release of phenol pollutants.

Fabrication of polymer-modified magnetic nanoparticle based adsorbents for the capture and release of quinolones by manipulating the metal-coordination interaction

Functional polymers with a metal-coordination interaction have been fabricated for sample pretreatment. Poly(N-4-vinyl-benzyl iminodiacetic acid-co-methacrylic acid-co-styrene)-modified magnetic nanoparticles were prepared and used as solid-phase extraction adsorbents for the analysis of quinolones by tuning the metal-coordination interaction. In the construction of the polymer-based adsorbents, functional monomer (N-(4-vinyl)-benzyl iminodiacetic acid) and comonomers (methacrylic acid and styrene) were fabricated onto the magnetic nanoparticles by free radical polymerization. Factors affecting the performance of the adsorbents were investigated, and the results revealed that Fe³⁺ played a vital role in the formation of metal-coordination adsorbents. Compared with other compounds, the resultant adsorbents displayed good selectivity to quinolones due to the metal-coordination complex (N-4-vinyl-benzyl iminodiacetic acid-Fe³⁺ -quinolones). Interestingly, the captured quinolones could be rapidly released by manipulating the metal-coordination interaction with Cu²⁺ . The linearity range for analysis of the test quinolones was 0.025-2.0 μg/mL (R²  > 0.999), and the recovery varied from 80.0 to 100.7%. Further, the proposed adsorbents were combined with high-performance liquid chromatography for the analysis of quinolones in real urine samples. The results demonstrated that the prepared adsorbents have good selectivity and sensitivity for quinolones, showing great potential for drug analysis in real samples.

Creating magnetic ionic liquid-molecularly imprinted polymers for selective extraction of lysozyme

A novel magnetic (Fe3O4) surface molecularly imprinted polymer (MIP) based on ionic liquid (IL) (Fe3O4@VTEO@IL-MIPs) was prepared for the selective extraction of lysozyme (Lys). As the functional monomer of the MIPs, an imidazolium-based IL with vinyl groups was prepared. It can provide multiple interactions with template molecules. The amount of IL was optimized (200 mg). Fourier transform infrared spectrometry (FT-IR), transmission electron microscopy (TEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA) and a vibrating sample magnetometer (VSM) were used to characterize the MIP. The results indicate the successful formation of an imprinting polymer layer. The concentration of Lys in the supernatant was determined by UV-vis spectrophotometry at a wavelength of 280 nm. The maximum adsorption capability of the MIP is 213.7 mg g-1 and the imprinting factor (IF) is 2.02. It took 2.5 h for the MIP to attain adsorption equilibrium. The structure of the protein was evaluated using circular dichroism (CD) spectra and UV-visible spectra. The adsorption performance was further investigated in detail by selective adsorption experiments, competitive rebinding tests, and reusability and stability experiments. Furthermore, it was utilized to separate the template protein from a mixture of proteins and real samples successfully because of the high adsorption capacity for Lys.

Magnetic protein imprinted polymers: a review

Protein imprinted polymers have received a lot of interest in the past few years because of their applications as tailor-made receptors for biomacromolecules. Generally, the preparation of these polymers requires numerous and time-consuming steps. But their coupling with magnetic nanoparticles simplifies and speeds up the synthesis of these materials. Some recent papers describe the use of protein imprinted polymer (PIP) coupled to magnetic iron oxide nanoparticles (MION) for the design of MION@PIP biosensors. With such systems, a target protein can be specifically and selectively captured from complex media due to exceptional chemical properties of the polymer. Despite such performances, only a limited number of studies address these hybrid nanosystems. This review focuses on the chemistry and preparation of MION@PIP nanocomposites as well as on the metrics used to characterize their performances.

Hydrogel Based Sensors for Biomedical Applications: An Updated Review

Biosensors that detect and convert biological reactions to a measurable signal have gained much attention in recent years. Between 1950 and 2017, more than 150,000 papers have been published addressing the applications of biosensors in different industries, but to the best of our knowledge and through careful screening, critical reviews that describe hydrogel based biosensors for biomedical applications are rare. This review discusses the biomedical application of hydrogel based biosensors, based on a search performed through Web of Science Core, PubMed (NLM), and Science Direct online databases for the years 2000⁻2017. In this review, we consider bioreceptors to be immobilized on hydrogel based biosensors, their advantages and disadvantages, and immobilization techniques. We identify the hydrogels that are most favored for this type of biosensor, as well as the predominant transduction strategies. We explain biomedical applications of hydrogel based biosensors including cell metabolite and pathogen detection, tissue engineering, wound healing, and cancer monitoring, and strategies for small biomolecules such as glucose, lactate, urea, and cholesterol detection are identified.

The controlled drug release by pH-sensitive molecularly imprinted nanospheres for enhanced antibacterial activity

In this study, we prepared pH-sensitive hybrid nanospheres through the implementation of a facile molecularly imprinted polymer (MIP) technique combined with a UV-initiated precipitation polymerization method using vancomycin (VA) for the templates. During the course of this investigation, both 2-hydroxyethyl methacrylate (HEMA) and 2-(diethylamino) ethyl methacrylate (DEAEMA) were utilized as the functional monomers, while ethylene glycol dimethacrylate (EGDMA) was used as a cross-linker. The obtained MIP nanospheres exhibited well-controlled particle size, with a drug loading capacity of about 17%, much higher than that of the non-imprinted polymer (NIP) nanospheres (5%). In addition, the VA loading quantity was closely correlated with the dosage of the cross-linking agent, and the MIP nanospheres exhibited a slower and more controlled VA release rate than the NIP nanospheres. Moreover, these MIP nanospheres were sensitive to pH values, and consequently showed an increasing release rate of VA as the pH level was decreased. The VA-loaded MIP nanospheres showed the higher antibacterial ratio of over 92% against Staphylococcus aureus (S. aureus) while the NIP nanospheres were friendly to S. aureus. These MIP nanospheres can be promising for targeting drug delivery system to achieve specific therapies such as preventing bacterial infections and killing cancer cells without damaging health cells and tissues.

Porous and Magnetic Molecularly Imprinted Polymers via Pickering High Internal Phase Emulsions Polymerization for Selective Adsorption of λ-Cyhalothrin

A novel macroporous magnetic molecularly imprinted polymer (MMIPs) of was prepared by W/O Pickering (high internal phase emulsions) HIPEs polymerization, and then it was adopted as adsorbent for selective adsorption of λ-cyhalothrin (LC). In static conditions, adsorption capacity of LC increased rapidly in the first 60 min and reached to equilibrium in ~2.0 h. Excellent conformity of the second-order model confirmed the chemical nature of the interaction between the LC and imprinted sites. The fitting adsorption isotherm was a Langmuir type, and the maximum monolayer adsorption capacity at 298 K was 404.4 μmol g⁻¹. Thermodynamic parameters suggested the specific adsorption at 298 K was an exothermic, spontaneous, and entropy decreased process. Competitive recognition studies of the MMIPs were performed with diethyl phthalate (DEP) and the structurally similar compound fenvalerate (FL), and the MMIPs, which displayed high selectivity for LC.

pH-Responsive magnetic metal-organic framework nanocomposites for selective capture and release of glycoproteins

Novel magnetic metal-organic framework nanocomposites with 1,4-phenylenebisboronic acid as both an organic ligand and a functional molecule are proposed for the first time as a new type of intelligent nanomaterial to selectively capture and release glycoproteins via pH-stimulus-response, and would be of great potential for use in bio-separation.

A surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat for selective removal of bilirubin

Electrospinning and surface molecular imprinting were used together to prepare a surface molecularly imprinted electrospun polyethersulfone (PES) fiber mat for selective removal of bilirubin.

Molecularly imprinted plasmonic nanosensor for selective SERS detection of protein biomarkers

Molecularly imprinted plasmonic nanosensor has been prepared via the rational design of an ultrathin polymer layer on the surface of gold nanorods imprinted with the target protein. This nanosensor enabled selective fishing-out of the target protein biomarker even from a complex real sample such as human serum. Sensitive SERS detection of the protein biomarkers with a strong Raman enhancement was achieved by formation of protein imprinted gold nanorods aggregates, stacking of protein imprinted gold nanorods onto a glass plate, or self-assembly of protein imprinted gold nanorods into close-packed array. High specificity and sensitivity of this method were demonstrated with a detection limit of at least 10(-8)mol/L for the target protein. This could provide a promising alternative for the currently used immunoassays and fluorescence detection, and offer an ultrasensitive, non-destructive, and label-free technique for clinical diagnosis applications.

Preparation and characterization of biocompatible molecularly imprinted poly(ionic liquid) films on the surface of multi-walled carbon nanotubes

A series of novel biocompatible MIPs were synthesized for BSA recognition by using MWCNTs with different outside diameters as substrates, and allyl-functionalized ionic liquids with different anion species as monomers.

A biomimetic Setaria viridis-inspired imprinted nanoadsorbent: green synthesis and application to the highly selective and fast removal of sulfamethazine

The preparation of biomimetic Setaria viridis-inspired hydrophilic magnetic imprinted nanoadsorbent, via a two-step surface-initiated ATRP in a green alcohol/water solvent at RT, with MHNTs used as nano-cores, was first reported.

Surface protein imprinted magnetic nanoparticles for specific recognition of bovine hemoglobin

Magnetic molecular imprinting for recognition of bovine hemoglobin was prepared by combining the surface imprinting technique with two-stage core–shell sol–gel polymerization.

Fabrication of Surface Protein-Imprinted Nanoparticles Using a Metal Chelating Monomer via Aqueous Precipitation Polymerization

Molecular imprinting is a promising way for constructing artificial protein recognition materials, but it has been challenged by difficulties such as restricted biomacromolecule transfer in the cross-linked polymer networks, and reduced template-monomer interactions that are due to the required aqueous media. Herein, we propose a strategy for imprinting of histidine (His)-exposed proteins by combining previous approaches such as surface imprinting over nanostructures, utilization of metal coordination interactions, and adoption of aqueous precipitation polymerization capable of forming reversible physical crosslinks. With lysozyme as a model template bearing His residues, imprinted polymer nanoshells were grafted over vinyl-modified nanoparticles by aqueous precipitation copolymerization of a Cu(2+) chelating monomer with a temperature-responsive monomer carried out at 37 °C, above the volume phase-transition temperature (VPTT) of the final copolymer. The imprinted nanoshells showed significant temperature sensitivity and the template removal could be facilitated by swelling of the imprinted layers at 4 °C, below the VPTT. The resultant core-shell imprinted nanoparticles exhibited strikingly high rebinding selectivity against a variety of nontemplate proteins. An imprinting factor up to 22.7 was achieved, which is among the best values reported for protein imprinting, and a rather high specific binding capacity of 67.3 mg/g was obtained. Moreover, this approach was successfully extended to preliminary imprinting of hemoglobin, another protein with accessible His. Therefore, it may be a versatile method for fabrication of high-performance surface-imprinted nanoparticles toward His-exposed proteins.

Molecularly imprinted polymers for separating and sensing of macromolecular compounds and microorganisms

The present review article focuses on gathering, summarizing, and critically evaluating the results of the last decade on separating and sensing macromolecular compounds and microorganisms with the use of molecularly imprinted polymer (MIP) synthetic receptors. Macromolecules play an important role in biology and are termed that way to contrast them from micromolecules. The former are large and complex molecules with relatively high molecular weights. The article mainly considers chemical sensing of deoxyribonucleic acids (DNAs), proteins and protein fragments as well as sugars and oligosaccharides. Moreover, it briefly discusses fabrication of chemosensors for determination of bacteria and viruses that can ultimately be considered as extremely large macromolecules.