Rebinding Capacity Research Articles

Nanoscale trifunctional bovine hemoglobin for fabricating molecularly imprinted polydopamine via Pickering emulsions-hydrogels polymerization

In this work, a novel strategy was developed for the selective recognition of protein based on oil-in-water Pickering emulsions-hydrogels polymerization and interfacial imprinting method. For the first time, nanoscale trifunctional bovine hemoglobin (BHb) played three roles simultaneously during the process, including emulsifier, template protein and sacrificial material for further exposing recognition sites. Prior to acting as stabilizers, bovine hemoglobin colloidal particles (BCPs) were firstly prepared by acidification and heat denaturation. Then the BCPs acted as “surfactant” to stabilize the Pickering emulsions composed of functional monomers in the water phase. After dopamine polymerized, the template proteins were removed, forming the BHb imprinted cavities on the surface of the polymeric materials. During this process, the interfacial BCPs also fell off, leaving more imprinted cavities exposed. FT-IR spectroscopy confirmed that BCPs were completely removed from the synthesized imprinted materials. The interconnected macropores structures of the materials encouraged nearly all of the rebinding sites located on its surface. Thus the prepared Hydro-MIPs exhibited rapid and selective recognition toward BHb. Owing to the hierarchical porous structure, the BHb imprinted polymers based on Pickering emulsions-hydrogels (Hydro-MIPs) possessed enhanced rebinding kinetics, and the maximum rebinding capacity is 449mgg−1, 3.97 times higher than that of the non-imprinted polymers (Hydro-NIPs). Besides these, the regeneration ability test suggested that the Hydro-MIPs could be used repeatedly without distinct loss in adsorption capacity. Overall, the combination of high selectivity, good mass transfer efficiency, easy preparation and trifunctional BHb provide a new insight into bioseparation and proteomics research in biological area.

Synthesis and application of molecularly imprinted polymer for highly selective solid phase extraction trace amount of sotalol from human urine samples: Optimization by central composite design (CCD)

A novel method is described for trace determination of sotalol, a β-blocker drug, using molecularly imprinted solid-phase extraction (MISPE) coupled with high-performance liquid chromatography with UV detection (HPLC/UV). The synthesis of the molecularly imprinted polymer was performed using acrylamide, ethylene glycol dimethacrylate, dimethylformamide, 2,2′-azobisisobutyronitrile and sotalol as a functional monomer, cross-linker monomer, solvent, initiator, and target drug, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used for characterizing the synthesized polymers. Also, a central composite design under response surface methodology and chemometrics applied to investigate and optimize the molecularly imprinted solid-phase extraction procedure parameters such as pH, loading and eluent solvent flow-rate, eluent solvent volume and sorbent mass, that probably influence the extraction process, to achieve the highest sotalol extraction efficiency. Batch rebinding capacity of sotalol was determined from the derived Langmuir isotherm and was found to be 20.08 mg/g. At above specified conditions, the proposed MISPE-HPLC/UV method used for the separation of trace amounts of sotalol in human urine samples with acceptable high recoveries (97–102%) and RSD% lower than 5%. The limit of detection and limit of quantification of the method were 0.01 and 0.04 μg/mL, respectively.

Ion cum molecularly dual imprinted polymer for simultaneous removal of cadmium and salicylic acid.

Ion cum molecularly dual imprinted polymer (DMIP) was synthesized for the simultaneous removal of salicylic acid (SA) and cadmium (Cd) by suspension polymerization method using chitosan (CTS) as functional polymer, epichlorohydrin as cross-linker, and 4-hydroxy benzoic acid (4HBA) as well as Cd as organic and inorganic templates, respectively. Use of the dummy template 4HBA during the synthesis of DMIP had the advantage of creating imprinted cavities in DMIP, which depicted good uptake for SA. Scanning electron microscopy and Fourier transform infrared spectroscopy indicated successful preparation of DMIP. Particle size analysis confirmed polydispersity, and thermal and swelling studies indicated the mechanical stability in DMIP. The rebinding capacities of the DMIP for Cd and SA were found to be 38.46 and 23.81mgg-1 , respectively, under the optimize condition of the time, dose, and concentration. Adsorption isotherm results fitted into Langmuir adsorption isotherm model with the R2 values of 0.994 and 0.995 for Cd and SA, respectively. The presence of intramolecular hydrogen bonding in SA, stability of the template-monomer complexes (CTS-SA and CTS-4HBA), and the involvement of the hydroxyl groups on DMIP for the uptake of SA has been supported by molecular modeling studies using Gaussian 03 software. The electron doublet of the amino groups of DMIP was involved for the uptake of Cd. Lower binding efficiency of DMIP for SA as compared to Cd may be due to the partial participation of hydroxyl group in cross-linking with epichlorohydrin during the synthesis of DMIP.

Preparation of Toluene-Imprinted Homogeneous Microspheres and Determination of Their Molecular Recognition Toward Template Vapor by Inverse Gas Chromatography

A toluene-imprinted polymers (MIPs) homogeneous microsphere was prepared by precipitation polymerization technique using toluene as porogen (also as template) with 4-vinyl pyridine (4-VP) as the functional monomer. Structural characterization was performed by the nitrogen adsorption method and optical microscope utilized for observing particle size of polymers. Retention capability and selectivity for this MIP toward template vapor and its relative compounds were evaluated and the isotherm rebinding capacity of the MIP tested by adopting an inverse gas chromatography method. Results indicated that the toluene-imprinted polymer (MIP3), as a stationary phase in gas chromatography, possessed high retention selectivity toward template vapor, with a retention factor value of 68.42, an imprinting factor value of 7.049, and selectivity factor values of 4.821 and 5.370 for the template relative to benzene and p-xylene, respectively. A model mixture containing toluene, benzene, and p-xylene could be effectively separated, with a resolution of 5.138 for toluene to p-xylene and of 1.762 for toluene to benzene. The isotherm adsorption curve for the MIP3 toward toluene vapor exhibited II type of BET adsorption. Additionally, the toluene-imprinted microspheres showed satisfactory applicability in the removal of toluene from polluted indoor air.

New biosourced chiral molecularly imprinted polymer: Synthesis, characterization, and evaluation of the recognition capacity of methyltestosterone.

New biosourced chiral cross-linkers were reported for the first time in the synthesis of methyltestosterone (MT) chiral molecularly imprinted polymers (cMIPs). Isosorbide and isomannide, known as 1,4:3,6-dianhydrohexitols, were selected as starting diols. The cMIPs were synthesized following a noncovalent approach via thermal radical polymerization and monitored by Raman spectroscopy. These cross-linkers were fully characterized by 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. The cross-polarization magic angle spinning 13 C NMR, Fourier transform infrared spectroscopy, scanning electron microscopy, and specific surface areas following the Brunauer-Emmett-Teller (BET) method were used to characterize the cMIPs. The effect of stereochemistry of cross-linkers on the reactivity of polymerization, morphology, and adsorption-recognition properties of the MIP was evaluated. The results showed that the cMIP exhibited an obvious improvement in terms of rebinding capacity for MT as compared with the nonimprinted polymer (NIP). The highest binding capacity was observed for cMIP-Is (27.298mgg-1 ) for high concentrations (500mgL-1 ). However, the isomannide homologue cMIP-Im showed higher recovery-up to 65% and capacity for low concentrations (15mgL-1 ). The experimental data were properly fitted by the Freundlich adsorption isothermal model.

Bioinspired synthesis of pDA/SiO2-based porous ciprofloxacin-imprinted nanocomposite membrane by a polydopamine-assisted organic-inorganic method

Development of membrane-associated molecularly imprinted materials that can rapidly recognize and separate specific compounds has broad technological applications for areas ranging from sewage treatments to biomedical devices. However, issues such as low permselectivity and unstable composite structures are restricting it from developing stage to a higher level. Here, inspired by the bioadhesive technology of polydopamine (pDA), a novel porous pDA/SiO2-based molecularly imprinted nanocomposite membranes (PMINcMs) strategy was developed and obtained. The as-prepared PMINcMs were synthesized through an in situ AGET-ATRP method by using ciprofloxacin as template molecule. Importantly, largely enhanced specific rebinding capacity (64.54mg/g) and permselectivity (the permeability factor β was larger than 2.27) had be successfully achieved, which should be attributing to the formation of high-stability and uniform growth of ciprofloxacin-imprinted layers onto the pDA/SiO2-based surfaces. Additionally, the PMINcMs not only exhibited rapid adsorption dynamics of template molecule, but also possessed excellent regeneration performance. All synthesis methods were conducted in water at ambient temperature, which was environmental friendly for scaling up without causing pollution.

Facile bio-functionalized design of thermally responsive molecularly imprinted composite membrane for temperature-dependent recognition and separation applications

It is becoming significant needed that ‘smart membranes’ with specific recognition sites can rapidly change flow rates in response to external stimuli. Herein, inspired by a mussel-inspired two-step surface synthesis methodology, we have reported a novel system for harvesting thermally responsive molecularly imprinted composite membranes (TMICMs) with excellent selective adsorption and separation performance toward template molecules. A self-polymerized polydopamine coating process was initially conducted to obtain the highly adjustable active surfaces. The TMICMs were then prepared through an in situ photoinitiated ATRP method by using N-isopropylacrylamide (NIPAm) as the thermo-responsive backbone monomer. Attributing to the formation of the polydopamine coating surfaces, remarkably enhanced rebinding capacity (2.343mmolcm−2) was obtained. Importantly, the as-prepared TMICMs with thermo-responsive “specific recognition sites” also exhibited excellent temperature-dependent switching modes for selective recognition and separation of the template molecule (ciprofloxacin). Meanwhile, this bioinspired thermo-responsive method could not only present an outstanding permselectivity property (separation factor β was more than 4.0), but also showed excellent structural stability and adsorption regeneration performance (the TMICMs could still possessed 92.74% of the maximum adsorption capacity after four adsorption/desorption cycles). Finally, we envision that the developed bio-adhesive platform synthesis strategy employed in this case can be utilized in a broad range of applications and will have a great impact on the fields of fluid handling, thermo-responsive sensors, membrane-based drug delivery and separation.

Accelerating the design of gold/polymers/silica-based imprinted nanocomposite for light-triggered recognition and separation of biomolecules

Development of nanocomposites with environmentally response-type affinity sites, which can rapidly change the recognition rates in response to external, noninvasive stimuli, has broad technological applications for areas. In this work, inspired by a polydopamine (pDA) self-assembly strategy, a well-defined optically and thermally responsive silica/MIPs/gold nanocomposite (TO-MIPs) was successfully synthesized for the selective recognition and separation of sodium cholate hydrate (SCH). The design and engineering of these smart materials was achieved through the coupling of pDA-modified SiO2 surfaces with poly(N-isopropyl acrylamide) (PNIPAm)-based SCH-imprinted layers that can change their physical conformation in response to heat. The TO-MIPs were finally synthesized by being coupled with Au nanoparticles (the sensitive light-heat converter) through an in situ reduction of metallic salts. Importantly, largely enhanced rebinding capacity (37.87mg/g) and regeneration performance were both achieved. Moreover, with the opto-thermally responsive ‘specific recognition sites’, the as-prepared TO-MIPs not only exhibited rapid specific adsorption dynamics, but also possessed opto-thermally responsive separation performance of SCH. This biologically inspired methodology processed high durability and regeneration performance and was capable of reversibly controlling specific binding capacities of SCH from 11.76 to 35.79mg/g in less than 5min using the noninvasive stimulus of light. Additionally, the whole synthesis procedures were conducted in aqueous solution at low temperature, which are environmental friendly for scaling up without pollution.

A novel approach toward fabrication of porous molecularly imprinted nanocomposites with bioinspired multilevel internal domains: Application to selective adsorption and separation membrane

The development of membrane-associated molecularly imprinted materials that can rapidly adsorb and separate specific compound has broad technological applications for areas ranging from sewage treatments to biomedical devices. However, issues such as low permselectivity and unstable composite structures are restricting it from developing stage to a higher level. Here, inspired by the bioadhesive technology of polydopamine (pDA), we present a novel molecular imprinting strategy to integrate multilevel nanocomposites (Br-Ag-pDA@SiO2) into the porous membrane structure. The molecularly imprinted nanocomposite membranes (MINcMs) were then obtained through an in situ photoinitiated ATRP method by using propranolol as the template molecule, which was one of the pharmaceutically active compounds (PhACs). In this work, largely enhanced specific rebinding capacity (48.53mg/g) and permselectivity (the permeability factor β values were also more than 9.6) had been successfully achieved, which should be attributing to the creation of high-stability and uniform growth of propranolol-imprinted polymer layers onto the nanoparticle-integrated nanocomposite membrane surfaces. Specifically, the as-prepared MINcMs not only exhibited rapid adsorption dynamics of template molecule, but also possessed excellent regeneration performance. Moreover, when the other PhACs were respectively imprinted, similar recognition selectivity could be observed dependent on the template molecule. Importantly in this case, all synthesis methods were conducted in aqueous at ambient temperature, which was environmental friendly for scaling up without causing pollution.

Preparation of Tetracycline Surface Molecularly Imprinted Material for the Selective Recognition of Tetracycline in Milk

Silica particles were modified with 3-methacryloxypropyl trimethoxysilane (MPS) as a carrier material. The tetracycline (TC) molecular imprinting polymer based on the surface of modified silica (MPS/SiO2) was prepared by adopting the novel surface molecular imprinting technique with tetracycline as template molecule and ethylene glycol diglycidyl ether (EGDE) as crosslinker. The rebinding capacity of molecularly imprinted polymer (MIP) was evaluated according to the adsorption kinetics and the adsorption isotherm. The two distinct linear portions in Scatchard analysis indicate that two classes of binding sites existed in the imprinted polymer. The MIP obtained was used as a selective sorbent for molecularly imprinted solid-phase extraction (MISPE) prior to HPLC analysis. The results showed that good linearity was observed in the range of 150∼950 μg/L for TC, with a correlation coefficient of 0.9972. Adding level of 300∼700 μg/L, the average of spiked recoveries of TC is about 81.1 %, with a relative standard deviation (RSD) range from 3.0 to 4.4 %, and the limit of detection (LOD) reached 25 μg/L. The proposed method is easy to operate, reliable, and applicable to analyze the TC residues in milk samples.

The effect of crosslinking density on molecularly imprinted polymer morphology and recognition

In this report, the crosslinking density of bupivacaine molecularly imprinted methacrylic acid (MAA)–ethylene glycol dimethacrylate (EGDMA) copolymers was investigated through replacement of EGDMA by methyl methacrylate (MMA). The effects were examined using a series of full-scale MD simulations of pre-polymerization mixtures, equilibrium rebinding studies on the corresponding synthesized polymers and morphology characterization through nitrogen sorption measurements. While the extent of hydrogen bonding between the functional monomer MAA and bupivacaine observed in the MD pre-polymerization mixtures was comparable in each of the systems studied, the decrease in degree of crosslinking impacted directly on polymer morphology as observed in BET and BJH studies of surface area and porosity. Further, decreases in the crosslinking density induced reductions in template rebinding capacity as seen from a series of radio-ligand binding studies, demonstrating the importance of crosslinking on the performance of molecularly imprinted MAA–EGDMA copolymers, the polymer system most commonly used in molecular imprinting science and technology.

Development of a sandwich-type filtration unit packed with MIP nanoparticles for removal of atrazine from water sources

Highly specific molecularly imprinted polymer (MIP) nanoparticles (NPs) were synthesized via precipitation and mini-emulsion polymerization in the presence of atrazine, acting as template molecule. The specificity and binding ability of synthesized MIP NPs to remove the target template molecule from polluted water samples were tested in batch-wise experiments. Subsequently, a sandwich-type membrane filtration system packed with highly specific particulate MIPs was developed for the selective adsorption of atrazine from water samples. The sandwich-type fixed bed filtration unit packed with MIP NPs was then tested in continuous filtration experiments for the removal of atrazine from water samples at very low concentrations (i.e., down to 1ppb). The binding capacity of the regenerated sandwich-type filtration system packed with MIP NPs and its long-term performance was also assessed through a series of experiments. It was found that the sandwich-type fixed bed filtration unit packed with MIP NPs synthesized by mini-emulsion polymerization can efficiently remove atrazine from water samples at very low concentrations and it can be regenerated and reused without loss of the rebinding capacity and “memory effect”. Finally, a simple kinetic model was developed to describe the atrazine adsorption rate from aqueous solutions. Based on the derived kinetic model, it was found that 0.75g of MIP NPs were required for the removal of 99% of the total atrazine mass from a polluted water quantity of 800ml (i.e., 1–10ppb atrazine concentration) flowing through the filtration unit at a rate 4ml/min.

Highly selective nanocomposite sorbents for the specific recognition of S-ibuprofen from structurally related compounds

The aim of the present work was to synthesize highly homogeneous synthetic recognition units for the selective and specific separation of S-ibuprofen from its closely related structural analogues using molecular imprinting technology. The molecular imprinted polymer wrapped on functionalized multiwalled carbon nanotubes (MWCNT-MIP) was synthesized using S-ibuprofen as the template in the imprinting process. The characterization of the products and intermediates were done by FT-IR spectroscopy, PXRD, TGA, SEM and TEM techniques. The high regression coefficient value for Langmuir adsorption isotherm (R 2 = 0.999) showed the homogeneous imprint sites and surface adsorption nature of the prepared polymer sorbent. The nano-MIP followed a second-order kinetics (R 2 = 0.999) with a rapid adsorption rate which also suggested the formation of recognition sites on the surface of MWCNT-MIP. MWCNT-MIP showed 83.6 % higher rebinding capacity than its non-imprinted counterpart. The higher relative selectivity coefficient (k′) of the imprinted sorbent towards S-ibuprofen than that for its structural analogues evidenced the capability of the nano-MIP to selectively and specifically rebind the template rather than its analogues.

Molecularly imprinted polymer layers using Navicula sp. frustule as core material for selective recognition of lysozyme

Surface molecular imprinting onto supported materials is particularly suitable for bulky structure template like protein. Inspired by this method, diatom frustules (Navicula sp. frustules) were used for the first time as supported material due to its unique properties of moderate surface area, reproducible with exactness in vast numbers and biocompatible, in order to address the limitation of nanoparticle as core material with low adsorption capacity. The molecular imprinting on Navicula sp. frustules was synthesized using polyacrylamide incorporate with two charged monomers and LYZ as template. The effect of synthesis conditions such as molar ratio of monomers and feed crosslinking degree were examined. With the optimal crosslinking degree (50%) and molar ratio of monomers (1/0.5/0.5), the LYZ-imprinted frustules exhibited enhancement in both rebinding capacity (124±1.09mgg−1) and imprinting factor (2.99), without showing significant decrease in adsorption kinetics (within 15min) when compared to work of other research groups. Additionally, template removal during LYZ-imprinted frustules synthesis as well as desorption after rebinding was achieved via mildly washing with salt solution. The outstanding recognition, rebinding and desorption performance suggested that Navicula sp. frustules are potential core material for surface molecular imprinting in the application of medical diagnostics.

Novel molecularly imprinted polymer prepared by palygorskite as support for selective adsorption of bisphenol A in aqueous solution

Novel strategy to synthesize palygorskite-supported surface molecularly imprinted polymer (SMIP) for bisphenol A (BPA) template was presented. Fourier transform infrared, scanning electron microscopy, and elemental analysis were employed for the characterization of the resulting composites. When compared with the molecularly imprinted polymer, the SMIP exhibited more excellent affinity and selectivity towards BPA in aqueous solution, with the affinity constant (b) of 1.929, the Freundlich constants (KF) of 25.758, and the distribution coefficient (Kd) of 128.390. The adsorption behaviors of the SMIP were well described by Freundlich isotherm model and the pseudo-second-order model. Moreover, the sustainable reusability of the SMIP without significant loss in rebinding capacity was affirmed in four repeated cycles. These results demonstrated the potential of the prepared SMIP as an advanced separation materials for the elimination of specific endocrine disruptor in aquatic environment.

Preparation and rebinding properties of protein-imprinted polysiloxane using mesoporous calcium silicate grafted non-woven polypropylene as matrix.

Calcium silicate particle containing mesoporous SiO2 (CaSiO3@SiO2) was grafted on the surface of non-woven polypropylene. The PP non-woven grafted calcium silicate containing mesoporous SiO2 (PP-g-CaSiO3@SiO2) was used as the matrix to prepare bovine serum albumin (BSA) molecularly imprinted polysiloxane (MIP) by using silanes as the functional monomers and BSA as the template. PP non-woven grafted BSA-imprinted polysiloxane (PP-g-CaSiO3@SiO2 MIP) was characterized by scanning electron microscope (SEM), Fourier transform infrared spectometry (FTIR) and drilling string compensator (DSC). Influence factors on the rebinding capacity of the MIP were investigated, such as grafting degree, the pH in treating CaSiO3 and the type and proportion of silanes. The rebinding properties of BSA on PP-g-CaSiO3@SiO2 and MIP were investigated under different conditions. The results indicated that the rebinding capacity of MIP for BSA reached 56.32 mg/g, which was 2.65 times of NIP. The non-woven polypropylene grafted BSA-imprinted polysiloxane could recognize the template protein and the selectivity factor (β) was above 2.4 when using ovalbumin, hemoglobin and γ-globulin as control proteins. The PP-g-CaSiO3@SiO2 MIP has favorable reusability.

Determination of dimetridazole using carbon paste electrode modified with aluminum doped surface molecularly imprinted siloxane

For the first time, a simple and highly sensitive electrochemical dimetridazole (DMZ) sensor based on a carbon paste electrode modified with core-shell aluminum doped surface molecularly imprinted siloxane has been developed and tested. Because of aluminum doping, the surface imprinting sensor exhibits higher rebinding capacity, recognition ability and affinity for DMZ in comparison with the aluminum free and the non-imprinted ones. In addition, the as-prepared sensor shows good stability and satisfactory reproducibility for the determination of DMZ. Under optimal experimental conditions, the peak currents by differential pulse stripping voltammetry were found to vary linearly with DMZ concentrations in the range from 1.0×10−8 to 1.0×10−6molL−1 and 1.0×10−6 to 1.0×10−4molL−1, with a detection limit of 3.6×10−9molL−1. This sensor was successfully employed to detect DMZ in egg, milk powder, and pig feed samples with acceptable recoveries of 91.4% to 107.6%, which was verified by high performance liquid chromatography.

Preparation and adsorption characteristics of surface-imprinted polymer using bovine serum albumin and lysozyme as double template proteins

The double template surface-imprinted polymer (Bi-MIP)) was synthesized by atom transfer radical polymerization (ATRP) in aqueous media, using bovine serum albumin (BSA) and lysozyme (Lyz) as the template prteis, X-isopropylacrylamide (NIPAAm) and acrylamide (AAm) as the monomers and X-3-(dimethylamino) propyl-methacrylamide (DMAPMA) as the assistant of basic functional monomner. The ATHP possessed the mild reaction conditions and can be initiated at room temperature without heating and ultraviolet radiations. The preparation conditions of imprinted polymer were optimized, and the content of DMAPMA as the assistant of basic functional monomer was investigated. The results showed that Bi-MIP exhibited the good adsorption capacity and selectivity in single protein solution and in mixed protein solution when the volume of DMAPMA in the preparation process of Bi-MIP was 20 µL. The rebinding capacity of Bi-MIP was evaluated according to adsorption isotherm of the imprinted polymer. The Langmir adsorption model was employed to describe the isotherms and revealed that Bi-MIP exhibited the maximum rebinding to 13SA and Lyz at 10.2 mg g and 19.2 mg/g, respectively. And Bi-MIP had good imprinting effect and adsorption capacity to templates BSA and Lyz from egg white and bovine serum samples. This will provide a new way for specific recognition of the double multiple target proteins in the complex biological samples.

A functional monomer is not enough: principal component analysis of the influence of template complexation in pre-polymerization mixtures on imprinted polymer recognition and morphology.

In this report, principal component analysis (PCA) has been used to explore the influence of template complexation in the pre-polymerization phase on template molecularly imprinted polymer (MIP) recognition and polymer morphology. A series of 16 bupivacaine MIPs were studied. The ethylene glycol dimethacrylate (EGDMA)-crosslinked polymers had either methacrylic acid (MAA) or methyl methacrylate (MMA) as the functional monomer, and the stoichiometry between template, functional monomer and crosslinker was varied. The polymers were characterized using radioligand equilibrium binding experiments, gas sorption measurements, swelling studies and data extracted from molecular dynamics (MD) simulations of all-component pre-polymerization mixtures. The molar fraction of the functional monomer in the MAA-polymers contributed to describing both the binding, surface area and pore volume. Interestingly, weak positive correlations between the swelling behavior and the rebinding characteristics of the MAA-MIPs were exposed. Polymers prepared with MMA as a functional monomer and a polymer prepared with only EGDMA were found to share the same characteristics, such as poor rebinding capacities, as well as similar surface area and pore volume, independent of the molar fraction MMA used in synthesis. The use of PCA for interpreting relationships between MD-derived descriptions of events in the pre-polymerization mixture, recognition properties and morphologies of the corresponding polymers illustrates the potential of PCA as a tool for better understanding these complex materials and for their rational design.

Enhanced surface imprinting of lysozyme over a new kind of magnetic chitosan submicrospheres

Surface protein imprinting over nano- or micron-sized substrates is an effective approach for improving the biomacromolecule mass transfer and rebinding capacity. For achieving high recognition performance, it is necessary to introduce certain functional groups onto the surface of the support materials which can interact with the template protein. Herein, we report a surface protein imprinting approach using a new kind of core–shell magnetic chitosan submicrospheres as the supports. The surface of these magnetic chitosan particles is tethered with uncross-linked chitosan chains, hence bearing plenty of amino and hydroxyl groups, where a large amount of functional ligands can be readily coupled for capturing of the protein template. With lysozyme as a model print protein, the magnetic supports were functionalized with maleic acid and then coated with imprinted polymer layers. The resulting imprinted microspheres show significantly selective rebinding for lysozyme. In particular, they exhibit a specific rebinding capacity about three times higher than achieved with our previous lysozyme-imprinted particles synthesized in similar way but with maleic acid modified silica nanoparticles as the supports. This can be attributed to the much higher template binding capacity to the modified magnetic chitosan submicrospheres. Also, the resultant imprinted particles can be easily collected by a magnet. Therefore, such kind of chitosan submicrospheres may be a versatile carrier for constructing high-capacity and magnetically recyclable surface protein-imprinted particles.