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1.
《Electrophoresis》2018,39(2):356-362
In this work, a simple and rapid approach was developed for separation and detection of chiral compounds based on a magnetic molecularly imprinted polymer modified poly(dimethylsiloxane) (PDMS) microchip coupled with electrochemical detection. Molecularly imprinted polymers were prepared employing Fe3O4 nanoparticles (NPs) as the supporting substrate and norepinephrine as the functional monomer in the presence of template molecule in a weak alkaline solution. After extracting the embedded template molecules, Fe3O4@polynorepinephrine NPs (MIP–Fe3O4@PNE NPs) showed specific molecular recognition selectivity and high affinity towards the template molecule, which were then used as stationary phase of microchip capillary electrochromatography for chiral compounds separation. Mandelic acid and histidine enantiomers were used as model compounds to test the chiral stationary phase. By using R‐mandelic acid as the template molecule, mandelic acid enantiomer was effectively separated and detected on the MIP‐Fe3O4@PNE NPs modified PDMS microchip. Moreover, the successful separation of histidine enantiomers on the MIP–Fe3O4@PNE NPs modified microchip using L‐histidine as template molecule was also achieved.  相似文献   

2.
A generalized preparation procedure of open tubular (OT) molecule imprinted polymer (MIP) columns is proposed for a number of templates with acidic functionality such as profen drugs and others. The template (S‐enantiomer) was mixed with methacrylic acid, ethylene glycol dimethacrylate and 4‐styrenesulfonic acid, dissolved in a porogen mixture of ACN/2‐propanol (9/1), and incubated in a pretreated and silanized fused silica capillary by the thermal non‐covalent polymerization procedure. The whole preparation procedure was exactly the same for all the MIP capillaries except for the selection of template. Nevertheless, the morphologies of the MIP layers were markedly variant depending upon the choice of template. The separation efficiency of each OT‐MIP column for chiral separation of R‐ and S‐enantiomers was examined and tuned to obtain the best separation efficiency by changing the chromatographic parameters such as eluent composition and pH. Different optimized conditions were obtained for different OT‐MIP columns. Nevertheless, a unified eluent could be used to obtain still quite satisfactory results. Non‐chiral separation of the MIP columns were also examined in the unified eluent with two sets of test mixtures, that is, a mixture of alkylbenzenes and a mixture of small polar solutes. The chiral and non‐chiral separation of this study resulted in very good separation efficiencies. This work is the very first study for the generalization of preparation of OT‐MIP columns for a number of templates.  相似文献   

3.
This article describes for the first time the development of a new polymerization technique by introducing iniferter‐induced “living” radical polymerization mechanism into precipitation polymerization and its application in the molecular imprinting field. The resulting iniferter‐induced “living” radical precipitation polymerization (ILRPP) has proven to be an effective approach for generating not only narrow disperse poly(ethylene glycol dimethacrylate) microspheres but also molecularly imprinted polymer (MIP) microspheres with obvious molecular imprinting effects towards the template (a herbicide 2,4‐dichlorophenoxyacetic acid (2,4‐D)), rather fast template rebinding kinetics, and appreciable selectivity over structurally related compounds. The binding association constant Ka and apparent maximum number Nmax for the high‐affinity sites of the 2,4‐D imprinted polymer were determined by Scatchard analysis and found to be 1.18 × 104 M?1 and 4.37 μmol/g, respectively. In addition, the general applicability of ILRPP in molecular imprinting was also confirmed by the successful preparation of MIP microspheres with another template (2‐chloromandelic acid). In particular, the living nature of ILRPP makes it highly useful for the facile one‐pot synthesis of functional polymer/MIP microspheres with surface‐bound iniferter groups, which allows their direct controlled surface modification via surface‐initiated iniferter polymerization and is thus of great potential in preparing advanced polymer/MIP materials. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3217–3228, 2010  相似文献   

4.
A molecularly imprinted polymer (MIP), with special molecule recognition properties of ciprofloxacin (CIP), was prepared by thermal polymerization in which ciprofloxacin acted as template molecule, α-methacrylic acid (MAA) acted as functional monomer and trimethylolpropane trimethylacrylate (TRIM) acted as crosslinker. The optimized ratio was determined to be n(CIP): n (MMA):n(TRIM)51:6:16 by investigation of the effects of different concentrations of functional monomer and the crosslinker on the MIP’s recognition properties. Equilibrium binding experiment was used to investigate the adsorption dynamics, the binding ability to template molecule and the substrate selectivity. Scatchard analysis was used to study the MIP’s binding characteristic to template molecule. The results indicated that MIP has higher adsorption ability and selectivity. The equilibrium distribution coefficient K D was 41.64 and the separation factor α was 1.62. Scatchard analysis showed that two different kinds of binding sites were produced in the polymer matrix and their dissociation constants were calculated to be K d1 = 5.249 × 10−5 mol·L−1, K d2 = 2.237 × 10−3 mol·L−1. __________ Translated from Chemistry, 2008, 71(2): 132–137  相似文献   

5.
Functional polystyrene (PS) crosslinked microbeads were developed by dispersion polymerization as fluorescent molecularly imprinted polymers (MIPs) having cavities with specific recognition sites. The functional azobenzene molecule modified with pyridine was self‐assembled with Pyrenebutyric acid (template molecules), and introduced during the second stage of dispersion polymerization of polystyrene. The template molecule was removed from MIP by Soxhlet using acetonitrile as solvent. Non imprinted polymer (NIP) having no template was also synthesized for comparative study. Fluorescence spectroscopy could be used as a tool to derive insight into the location of the template molecules on the MIP or NIP. The template molecules were adsorbed on the surface of the NIPs during binding studies, which was evidenced from the pyrene excimeric emission observed at 440 nm. The template binding efficiency of the NIPs were much lower compared to MIPs. Pyrene emission from MIP upon rebinding showed typical monomeric emission in the 375–395 nm range, confirming its location in isolated cavities. In rebinding studies of the template molecules, the MIPs selectively took up the template for which the cavity was designed, which demonstrated their selectivity towards template molecules. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1558–1565  相似文献   

6.
Lysozyme-imprinted polymer synthesized using UV free-radical polymerization   总被引:1,自引:0,他引:1  
Yu S  Luo AQ  Biswal D  Hilt JZ  Puleo DA 《Talanta》2010,83(1):156-161
Molecular imprinting is a method to fabricate a polymeric material (molecularly imprinted polymer or MIP) capable of selectively recognizing template molecules. Molecular imprinting of small molecules has been studied widely. Less common, however, is the imprinting of biological macromolecules, including proteins, among which lysozyme is an important molecule in the food, pharmaceutical, and diagnostic sciences. In this study, lysozyme MIP was fabricated in two steps. First, lysozyme, PEG600DMA, and methacrylic acid were used as the template molecule, cross-linking monomer, and the functional monomer, respectively, in a UV free-radical polymerization process to synthesize a polymeric gel. Second, lysozyme was removed by enzymatic digestion. Non-imprinted polymer (NIP) was synthesized without lysozyme addition. To evaluate the preferential binding capability of MIP, lysozyme, RNase A, or a 50:50 mixture of lysozyme and RNase A was added to MIP and NIP and then released by digestion. It was found that when more lysozyme was added to the reaction mixture, the quantity of protein released from the polymer increased, reflecting more potential binding sites. Tests of MIP with a competitive binding mixture of lysozyme and RNase A showed the MIP preferentially bound a greater amount of lysozyme, up to 20 times more than RNase A. NIP bound only small amounts of both proteins and did not show a preference for binding either lysozyme or RNase A. These results demonstrate that lysozyme was successfully imprinted into the MIP by UV free-radical polymerization, and the fabricated MIP was able to preferentially bind its template protein.  相似文献   

7.
In this work, poly(methacrylic acid) (PMAA)-based molecularly imprinted polymer nanoparticles (MIP NPs) using isosorbide dinitrate (ISDN) as a template were prepared via a precipitation polymerization. The morphology and performance of the samples were investigated by varying different concentrations of azobisisobutyronitrile (AIBN) as an initiator. The MIP NP sample characterization as a function of the initiator concentration was evaluated utilizing Fourier transform infrared (FTIR) spectroscopy and field emission-scanning electron microscopy (FE-SEM) analyses. Regarding the washed MIP NP samples, the FTIR spectra results showed two main characteristic peaks located at 3339 and 1734 cm?1 wavenumbers corresponding to hydroxyl (–OH) and carbonyl (–C=O) groups, respectively. The intensity of these main peaks for the washed MIP NPs was higher than that of those for unwashed MIP NPs in which the active sites were appropriately formed between the polymer and template. These observations were occurred at the maximum amount of AIBN concentration (3 mmol). Moreover, the FE-SEM micrograph images exhibited an average diameter of approximately 40 nm for the MIP NP sample prepared with a low concentration of the initiator (0.5% of polymerizable double bonds). Furthermore, another two key factors for the MIP NPs such as binding capacity, and surface area using Barrett–Joyner–Halenda (BJH) method were studied to apply them for drug delivery systems potentially. On the other hand, the release of ISDN from MIP NP was considered through phosphate buffer saline (PBS, pH 7.4) at 37 °C for 5 days. The results showed higher ability of the sample compared with the non-imprinted polymer (NIP) ones to control the drug release, and kinetic trend of the drug absorption within the MIP NPs followed the pseudo-first model. Finally, the obtained outcomes showed that the low amounts of the initiator concentration have an indispensable role on the physicochemical properties of the synthesized MIP NPs.  相似文献   

8.
A protein imprinting approach for the synthesis of core–shell structure nanoparticles with a magnetic core and molecularly imprinted polymer (MIP) shell was developed using a simple distillation–precipitation polymerization method. In this work, Fe3O4 magnetic nanoparticles were first synthesized through a solvothermal method and then were conveniently surface‐modified with 3‐(methacryloyloxy)propyltrimethoxylsilane as anchor molecules to donate vinyl groups. Next a high‐density MIP shell was coated onto the surface of the magnetic nanoparticles by the copolymerization of functional monomer acrylamide (AAm), cross‐linking agent N,N′‐methylenebisacrylamide (MBA), the initiator azodiisobutyronitrile (AIBN), and protein in acetonitrile heated at reflux. The morphology, adsorption, and recognition properties of the magnetic molecularly imprinted nanoparticles were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and rebinding experiments. The resulting MIP showed a high adsorption capacity (104.8 mg g?1) and specific recognition (imprinting factor=7.6) to lysozyme (Lyz). The as‐prepared Fe3O4@Lyz‐MIP nanoparticles with a mean diameter of 320 nm were coated with an MIP shell that was 20 nm thick, which enabled Fe3O4@Lyz‐MIP to easily reach adsorption equilibrium. The high magnetization saturation (40.35 emu g?1) endows the materials with the convenience of magnetic separation under an external magnetic field and allows them to be subsequently reused. Furthermore, Fe3O4@Lyz‐MIP could selectively extract a target protein from real egg‐white samples under an external magnetic field.  相似文献   

9.
利用辅助识别聚合物链制备牛血清白蛋白分子印迹聚合物   总被引:1,自引:0,他引:1  
论文提出了一种新的蛋白质分子印迹方法, 即以聚乙烯醇接枝聚合物作为辅助识别聚合物链(ARPCs), 以丙烯酰胺为单体, 在丙烯酸酯树脂载体表面进行聚合, 制备牛血清白蛋白分子印迹树脂. 实验使用2.00 mol•L−1氯化钾(KC1)溶液除去模板蛋白质, 使用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)检测吸附蛋白质, 并设计使用0.150, 0.500和2.00 mol•L−1KC1溶液分别对吸附蛋白质进行梯度洗提. 电泳实验结果表明, 2.00 mol•L−1KC1溶液洗脱的蛋白质是大孔树脂的吸附效应; 0.500 mol•L−1KC1溶液洗脱掉的是印迹蛋白质. 引入ARPCs制得的分子印迹树脂, 用于混合蛋白质体系吸附时, 对模板蛋白质的吸附量为80~100μg•g−1, 其特异性吸附能力较未引入ARPCs之前有明显提高.  相似文献   

10.
We introduce a new type of molecular imprinted polymer (MIP) with immobilized assistant recognition polymer chains (ARPCs) to create effective recognition sites. In this work, cloned pig cyclophilin 18 (pCyP18) and BSA were used as templates, respectively. The template protein was selectively assembled with ARPCs from the library which consists of numerous limited length polymer chains with randomly distributed recognition sites of the quaternary ammonium cationic groups and immobilizing sites. The assemblies of protein and ARPCs were adsorbed by macroporous microspheres and immobilized by cross‐linking polymerization. After removing the templates, the two kinds of synthesized MIPs were used to adsorb cloned pCyP18 and BSA from protein mixtures respectively and both showed high selectivity. It confirms that this new method is suitable to separate proteins of both low and high molecular weight. The extended experiment on adsorption of natural pCyP18 from cytosol shows that the obtained MIP using cloned protein as template can be used to enrich natural protein of low content.  相似文献   

11.
A new molecularly imprinted polymer (MIP) was prepared using methamidophos (MAP) as the template molecule based on non‐covalent interaction. The complexes formed between template and monomers before polymerization were characterized by 1H NMR titration test, FT‐IR and UV spectrometry study. These studies indicated that a 1:2 molecular complex formed dominantly between MAP and functional monomers. A model mainly involving cooperative hydrogen interaction was proposed by exact placement of functional groups. Association constant was estimated to be 2.894 × 106 L2/mol2. When the initial concentration of MAP was 1.0 mmol L?1, the affinity capacity of MIP was 4.23 times that of NIP. The binding performance of MIP was modeled with the Freundlich isotherm (FI) and the total number of binding sites was calculated to be 33.97 μmol/g. The MIP showed great homogeneity with a heterogeneity index of m = 0.7356. The specificity of MIP was investigated by single‐analyte binding and molecularly imprinted solid‐phase extraction (MISPE) assays using MAP and other structurally related organophorous pesticides (OPPs). The results indicated that the MIP had a marked preference for MAP.  相似文献   

12.
In this paper, a novel monolithic stir bar based on molecularly imprinted polymer (MIP) was firstly developed by filling modified neodymium magnet (Nd2Fe14B) powders into a glass tube (60 × 4 mm), followed by the imprinted grafting with bisphenol A (BPA) as the template molecule by thermal polymerization. It has been successfully used for the stir bar sorptive extraction (SBSE) and its extraction performance illustrated that the MIP‐encapsulated stir bar had stronger affinity to the template molecule, compared with the stir bar based on the non‐imprinted molecularly polymer (NIP). Under the optimal extraction conditions, a simple method based on the coupling of MIP‐SBSE with high performance liquid chromatography (HPLC) was used for the selective determination of the model mixtures of BPA, 4‐phenylphenol (PP) and phenol (P) in bottled water. The recoveries of BPA, PP and P were in the range of 88.5‐96.1%, 78.2‐89.7%, 81.3‐89.5% at three spiked levels, respectively, demonstrating that higher extraction and the specific absorption occurred between the template molecule and the prepared MIP stir bar.  相似文献   

13.
In the current paradigm for molecular imprinting, the imprinted binding sites exist as a consequence of the polymerization process around templates, and the properties of nonimprinted polymers (NIPs) have largely been overlooked. Thus, nothing can be affirmed a priori concerning the binding properties of NIPs. We propose an alternative view where the imprinting effect is due to the presence of a template molecule that enhances the pre-existing binding properties of a polymer. If a NIP shows no binding properties toward a target molecule, the corresponding imprinted polymer (MIP) will show a weak imprinting effect. On the other hand, if a NIP shows binding properties toward a target molecule, the corresponding MIP will show a significant imprinting effect. To verify this hypothesis, we prepared a 96-member combinatorial polymeric library in the absence of any template molecule. This library was screened for several potential ligands, and with no exceptions, the composition of the best-binding NIP produced a MIP with excellent binding properties, whereas a low-binding NIP formulation produced a MIP with comparable low binding. To validate these results, the binding properties toward naproxen and ibuprofen were measured for two combinatorial libraries of polymers prepared in the presence (MIP library) and the absence (NIP library) of the template molecule. The experiment's results showed a correlation between the apparent affinity constants measured for the NIP and MIP libraries, confirming the proposed hypothesis. Moreover, for closely related molecules, it was shown that binding selectivity is an emergent property derived from the imprinting process and not a property of NIPs.  相似文献   

14.
《Analytical letters》2012,45(15):2463-2481
Protein surface imprinting produces materials capable of selective recognition and capture of proteins. Herein, a protein surface imprinted polymer on graphene oxide modified super-paramagnetic Fe3O4 nanoparticles is reported. The molecularly imprinted polymer was synthesized by ultrasound-assisted suspension polymerization, using ovalbumin as the template molecule, 3-aminophenylboronie acid as the functional monomer, and methylene-bis-acrylamide as the cross-linking agent. The nanoparticles were approximately 40 nanometers in size and super-paramagnetic. Moreover, these particles demonstrated considerably high adsorption capacity, fast adsorption kinetics, and selective binding affinities toward the template protein ovalbumin. The calibration curve of ovalbumin was linear from 5.0 × 10?11 to 1.0 × 10?10 molar. The limit of detection of ovalbumin was 2.0 × 10?11 M. These results show that this super-paramagnetic material has potential for biological macromolecule separation and determination.  相似文献   

15.
A molecularly imprinted polymer (MIP) was synthesized and evaluated to selectively extract ephedrine from human plasma. The MIP synthesis was performed in chloroform with methacrylic acid as a functional monomer and the target alkaloid as a template molecule. The resulting MIP was applied to the selective extraction of ephedrine from a pure aqueous medium. A recovery about 74% was obtained using the MIP with only 7% on the nonimprinted polymer (NIP). A very straightforward selective SPE procedure was then successfully applied to the direct extraction of ephedrine from spiked human plasma with a high extraction recovery (68%) on the MIP with no recovery on the NIP. Moreover, the MIP was used for the selective extraction of catecholamine neurotransmitters, i.e. adrenaline and noradrenaline.  相似文献   

16.
A monolithic molecularly imprinted polymer (monolithic MIP) for sulfamethoxazole (SMO) was prepared by in situ polymerization method as the HPLC stationary phase. By optimizing the polymerization conditions, the monolithic MIP showed highly specific recognition for the template SMO over its three structurally related analogs. As shown by SEM and the pore size distribution profile, the resultant MIP monolith showed a main pore diameter of 594 nm and a large specific surface area of 124 m2 g−1, this allowed the mobile phase to flow through the column with low backpressure. Furthermore, the recognition abilities of the monolithic MIP in aqueous and organic media were studied. The results exhibited that the monolithic MIP possessed excellent recognition ability in aqueous media. Hydrophobic interactions, in addition to shape recognition, were the dominant effect for recognition in the mobile phase with high water content. Moreover, the binding sites and the dissociation constant were also determined by frontal chromatography as 122 μmol g−1 and 1.88 × 10−5 mol L−1, respectively, which demonstrated that the obtained SMO-MIP monolith had a high binding capacity and strong affinity ability to the template molecule. Furthermore, the resultant SMO-MIP monolith was used as HPLC column directly to determine the SMO contents in three kinds of pharmaceutical tablets with the optimized aqueous mobile phase.  相似文献   

17.
A novel approach to the manufacturing of protein‐responsive imprints on a home‐made chitosan substrate was established together with m‐aminophenylboronic acid (APBA) as a functional monomer. The produced polymers were characterized using both (1) equilibrium adsorption assays and (2) high performance liquid chromatography analysis. Results confirmed that the synthesized BSA‐MIP (molecularly imprinted polymer) has a high affinity towards its template compared to the determined control proteins. The produced BSA‐MIP featured largely in its good adsorption reversibility, especially in competitive binding assays, which is of great biological significance in separations. Non‐specific binding was reduced to almost zero in a BSA/BHb competitive binding event. An excellent HPLC profile of template recognition was found for BSA‐MIP, even under harsh mobile phase conditions. In the present work, the adopted trapped‐template‐release method permits recovery of bound BSA [1]. The strategy of making an artificial protein‐receptor with high adsorption affinity and reversibility is promising in on‐line isolation of target protein from complicated biological environments.  相似文献   

18.
An enzyme‐mediated synthetic approach is described for the preparation of molecularly imprinted polymer nanoparticles (MIP‐NPs) in aqueous media. Horseradish peroxidase (HRP) was used to initiate the polymerization of methacrylate or vinyl monomers and cross‐linkers by catalyzing the generation of free radicals. To prevent entrapment of the enzyme in the cross‐linked polymer, and to enable it to be reused, HRP was immobilized on a solid support. MIPs based on 4‐vinylpyridine and 1,4‐bis(acryloyl)piperazine for the recognition of 2,4‐dichlorophenoxyacetic acid (2,4‐D) and salicylic acid were synthesized in an aqueous medium. MIPs for the protein trypsin were also synthesized. MIP nanoparticles with sizes between 50 and 300 nm were obtained with good binding properties, a good imprinting effect, and high selectivity for the target molecule. The reusability of immobilized HRP for MIP synthesis was shown for several batches.  相似文献   

19.
This work was aimed to synthesize and characterize poly(2‐hydroxyethyl methacrylate) [poly (HEMA)]‐based molecularly imprinted polymer nanoparticles (MIP NPs) containing timolol maleate (TM) via precipitation polymerization. The molecular structures of the MIP and non‐imprinted polymer (NIP) NPs were compared by means of Fourier transform infrared spectroscopy. The morphological observations by using scanning electron microscopy and transmission electron microscopy confirmed the formation of MIP NPs as small as 128 nm in average diameter with appropriate synthesis conditions. Thermal behaviors of the samples were also studied by the use of thermogravimetric analysis and differential scanning calorimetry. By considering a series of key factors such as monomer : template ratio, cross‐linker type, pH, and temperature, the sample with promising characteristics was found to be that of HEMA : TM ratio of 10:1, 40 mmol of ethylene glycol dimethacrylate as cross‐linker, and polymerization temperature of 60°C in acetonitrile as porogenic solvent. Furthermore, the ultraviolet‐visible (UV‐vis) spectrophotometry results proved a controlled release of TM from the MIP NP samples compared with NIP ones at extended periods. Moreover, the cytotoxicity of the MIP and NIP NPs samples was evaluated on mesenchymal stem cells, and the obtained observations showed that they had no adverse side effect on the living cells; especially the surface of the MIP NPs sample depicted highly cell's biocompatibility. Finally, the outcomes from designed different experiments conducted us that the HEMA‐based MIP NPs have great potential as an ocular nanocarrier for TM delivery. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

20.
Despite the increasing number of applications of molecularly imprinted polymers (MIPs) in analytical chemistry, the construction of a biomimetic potentiometric sensor remains still challenging. In this work, a biomimetic potentiometric sensor, based on a non‐covalent imprinted polymer was fabricated for the recognition and determination of cetirizine. The MIP was synthesized by precipitation polymerization, using cetirizine dihydrochloride as a template molecule, methacrylic acid (MAA) as a functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross linking agent. The sensor showed high selectivity and a sensitive response to the template in aqueous system. The MIP‐modified electrode exhibited Nernstian response (28.0±0.9 mV/decade) in a wide concentration range of 1.0×10?6 to 1.0×10?2 M with a lower detection limit of 7.0×10?7 M. The electrode has response time of ca. 20 s, high performance, high sensitivity, and good long term stability (more than 5 months). The method was satisfactory and used to the cetirizine assay in tablets and biological fluids.  相似文献   

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