在硅胶表面制备牛血红蛋白分子印迹聚合物

采用表面印迹法, 以乙烯基三甲氧基硅烷修饰的硅胶为载体, 丙烯酰胺为功能单体, N,N-亚甲基双丙烯酰胺为交联剂, 并将改性聚乙烯醇(PVA)作为辅助识别聚合物链(ARPCs)引入聚合体系中, 制备了牛血红蛋白分子印迹聚合物(MIP). 实验使用红外光谱分析了改性PVA的结构特征, 用扫描电镜(SEM)观察MIP的表面形貌, 考察了ARPCs的含量对MIP吸附性能的影响. 吸附动力学实验研究表明, 聚合体系中ARPCs的引入使MIP对模板牛血红蛋白(BHb)的吸附量明显提高|十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)结果显示, MIP对BHb的特异性吸附能力明显提高.     

识别牛血红蛋白的分子印迹电化学传感器的制备与研究

采用电化学聚合物法制备了一种用于识别牛血红蛋白(BHb)的分子印迹电化学传感器。玻碳电极表面经电化学法沉积一层纳米金,接着自组装一层L-半胱氨酸,对修饰电极表面功能化,引入氨基和羧基,增加蛋白质印迹识别位点,以BHb为模板,采用电化学诱导的丙烯酰胺氧化还原聚合反应形成分子印迹聚合物层,模板蛋白分子经洗脱形成分子印迹电化学传感器。其产生的电化学信号的变化与BHb的质量浓度在1.0~1.0×103 mg·L~(-1)范围有直接的关系,检出限(3σ)达0.5mg·L~(-1)。这种新型传感器具有较高灵敏度,可用于目标蛋白的识别。     

牛血清白蛋白分子表面印迹材料的制备及其大分子识别特性研究

通过分子设计和过程策划,制备了高性能的牛血清白蛋白(BSA)分子表面印迹材料.首先以甲基丙烯酰氯为试剂,使交联聚乙烯醇(CPVA)微球表面的羟基发生酯化反应,将大量可聚合双键引入到CPVA微球表面.然后以含有可聚合双键的CPVA微球为载体,阳离子单体丙烯酰氧乙基三甲基氯化铵(DAC)为功能单体,N,N’-亚甲基双丙烯酰胺(MBA)为交联剂,牛血清白蛋白(BSA)为模板分子,在水溶液体系中,基于主-客体之间的强静电相互作用,采用接枝聚合与印迹过程同步进行的方式,制备了高性能BSA分子表面印迹微球MIP-PDAC/CPVA.采用红外光谱(IR)和扫描电子显微镜(SEM)对产物微球进行了表征.研究了印迹聚合物微球MIP-PDAC/CPVA对BSA的大分子识别特性.研究结果表明,微球MIP-PDAC/CPVA对BSA具有优良的结合亲和性和特异的识别选择性,结合容量高达108 mg/g,对牛血红蛋白(BHb)却基本不结合;相对于BHb,MIP-PDAC/CPVA对BSA的选择性系数高达60.2.     

光接枝表面修饰法制备牛血红蛋白的分子印迹微球

聚苯乙烯球载体表面经引发转移终止剂修饰后, 采用光接枝表面印迹方法制备了以牛血红蛋白(BHb)为模板分子、丙烯酰胺为功能单体和N,N′-亚甲基双丙烯酰胺为交联剂的分子印迹聚合物微球(MIP). 进一步采用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物微球进行了表征, 证实了载体表面成功地接枝了分子印迹层, 并研究了其吸附性能和分子识别选择性能. 结果表明, 采用光接枝表面修饰法制备的分子印迹微球对模板分子有着很好的吸附容量和识别选择性.     

硅胶修饰-表面分子印迹牛血红蛋白及其识别性能的研究

选用马来酸酐修饰的硅胶作为载体,丙烯酰胺为功能单体,N,N′-亚甲基双丙烯酰胺为交联剂,牛血红蛋白为模板分子,采用氧化还原悬浮聚合法,合成了具有选择性识别的牛血红蛋白分子印迹聚合物.并用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物进行了表征,结果表明载体表面成功地接枝了分子印迹聚合物薄层.同时选择性吸附实验表明分子印迹聚合物具有良好的识别性能,能实现水溶液中牛血红蛋白的富集.     

糖蛋白印迹二维光子晶体水凝胶传感器的构建

制备了一种特异性识别糖蛋白的二维光子晶体分子印迹水凝胶。以刀豆蛋白A(Con A)为模板分子,甲叉双丙烯酰胺(MBA)为交联剂,丙烯酰胺(AAm)与4-乙烯基苯硼酸为功能单体,N,N,N′,N′-四甲基乙二胺(TEMED)为引发剂,过硫酸铵(APS)为催化剂,在聚苯乙烯二维光子晶体(PC)表面产生聚合反应形成水凝胶,接着用10%的乙酸溶液洗脱模板分子,制备了可对Con A特异性识别的二维光子晶体分子印迹水凝胶(MIPs)传感器。结果表明,当MIPs的交联度为10%时,德拜环的直径变化最显著,对目标物的识别最灵敏。该传感器对Con A在0～0.5 mg/mL范围内具有良好的响应与识别能力,可用于目标物的富集和即时检测。同时,苯硼酸的引入,增加了印迹空穴的识别位点,进一步改善了印迹材料对糖类分子的特异识别性。该水凝胶传感器在卵清白蛋白(OVA)、牛血红蛋白(BHb)、溶菌酶(Lyz)、胰蛋白酶(Try)溶液中德拜环的直径变化远小于识别相同浓度的Con A引起的德拜环直径的变化,表现出良好的选择性。该方法操作简单,成本低廉,可重复使用,不需特殊仪器设备,可拓展到其它糖蛋白,实现糖类目标蛋白的...     

5-硝基-1H-吲哚-2-羧酸与牛血红蛋白相互作用的分子模拟与光谱研究

运用密度泛函理论B3LYP/6-31G*方法对5-硝基-1H-吲哚-2-羧酸(NIA)的几何构型进行了全优化.在这基础上,用分子对接技术确定了NIA与牛血红蛋白(BHb)之间的作用位点、作用力类型及相互作用能.理论计算的结果表明NIA和BHb相互作用的静电能是-208.9 kcal*mol-1,范德华能为-180.5 kcal*mol-1,势能为-389.4 kcal*mol-1.NIA与BHb中A链上的Leu129、Ser133残基形成氢键,而NIA分子中的骨架苯环部分易与疏水氨基酸,包括产生荧光的Tyr残基等发生作用,这与 NIA能使BHb荧光淬灭的实验结果是一致的.     

壳聚糖包裹硅胶载体印迹牛血红蛋白的研究

用壳聚糖包裹的硅胶为载体, 利用壳聚糖表面的氨基与戊二醛结合, 在硅胶表面引入醛基, 固定模板蛋白(牛血红蛋白). 用溶胶-凝胶过程再次包裹固定蛋白质的载体, 洗去模板蛋白后, 得到具有选择性识别的牛血红蛋白分子印迹聚合物. 用红外光谱(IR)、扫描电子显微镜(SEM)和元素分析对聚合物进行了表征, 结果表明, 载体表面成功地接枝了分子印迹聚合物. 选择性吸附实验结果表明, 分子印迹聚合物具有良好的识别性能, 能实现水溶液中牛血红蛋白的富集.     

修饰硅胶表面印迹牛血红蛋白及其识别性能的研究

本文选用马来酸酐修饰后的硅胶作为载体,丙烯酰胺为功能单体,N,N’-亚甲基双丙烯酰胺为交联剂,牛血红蛋白为模板分子,采用氧化还原悬浮聚合法,合成了具有选择性识别的牛血红蛋白分子印迹聚合物。并用红外光谱(IR)、扫描电子显微镜(SEM)对聚合物进行了表征,结果表明载体表面成功接枝了分子印迹聚合物薄层。同时,选择性吸附实验表明分子印迹聚合物的具有良好的识别性能,能成功的实现水溶液中牛血红蛋白的富集。     

汞(Ⅱ)与牛血红蛋白相互作用的研究

本文采用紫外光谱(UV/VIS)、荧光光谱和圆二色谱等方法,对汞(Ⅱ)与牛血红蛋白(BHb)的相互作用进行了研究.结果表明:Hg2 处理导致BHb紫外吸收的增加,出现LMCT带,并随Hg2 浓度的增加LMCT带强度显著增强.BHb分子中Soret带的吸收随着Hg2 作用时间的增加而持续降低,表明Hg2 使部分血红素辅基从BHb中脱离出来.蛋白内源荧光光谱显示,Hg2 与BHb的结合会影响蛋白质的三级结构和四级结构.远紫外圆二色谱表明,Hg2 处理会导致BHb蛋白的α-螺旋含量减少.     

Recognition and determination of bovine hemoglobin using a gold electrode modified with gold nanoparticles and molecularly imprinted self-polymerized dopamine

A molecularly imprinted polymer (MIP) was prepared by self-polymerization of dopamine in the presence of bovine hemoglobin (BHb) and then deposited on the surface of an electrode modified with gold nanoparticles (AuNPs). Scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry were employed to characterize the modified electrode using the hexacyanoferrate redox system as an electroactive probe. The effects of BHb concentration, dopamine concentration, and polymerization time were optimized. Under optimized conditions, the modified electrode selectively recognizes BHb even in the presence of other proteins. The peak current for hexacyanoferrate, typically measured at + 0.17 V (vs. SCE), depends on the concentration of BHb in the 1.0 × 10⁻¹¹ to 1.0 × 10⁻² mg mL⁻¹ range. Due to the ease of preparation and tight adherence of polydopamine to various support materials, the present strategy conceivably also provides a platform for the recognition and detection of other proteins.

Gold nanoparticles and molecularly imprinted self-polymerization dopamine were modified on gold electrode surface to recognize and determine bovine hemoglobin. Under the optimized conditions, the modified electrode showed specific adsorption, selective recognition, and sensitive detection of bovine hemoglobin.

     

分子印迹溶胶-凝胶材料的制备及应用

分子印迹技术是制备对特定分子具有选择性识别的聚合物的技术。分子印迹技术与溶胶-凝胶过程相结合,可设计多孔无机主体,增强分子识别能力,并具有极好的热稳定性和水解稳定性。改变溶胶-凝胶过程的条件,可制备具有最佳孔隙率和表面积,并用于分离复杂的混合物、选择性吸附富集模板分子(或目标分子)、催化、微合成器应用的分子印迹溶胶-凝胶材料。综述了溶胶．凝胶技术和分子印迹技术的特点,分子印迹溶胶-凝胶技术和分子印迹溶胶．凝胶材料的概念、基本原理、制备方法及应用。     

Organic–inorganic hybrid silica as supporting matrices for selective recognition of bovine hemoglobin via covalent immobilization

The synthesis of poly‐aminophenylboronic acid (APBA) imprinted hybrid silica‐based polymers for selective recognition of bovine hemoglobin (BHb) was described, where the mesoporous hybrid silica supporting matrices were prepared by a mild sol–gel process with tetraethoxysilane and 3‐aminopropyltriethoxysilane as two precursors. Covalent immobilization of BHb was adopted in order to create homogeneous recognition sites. After removal of the template, the resulting imprinted polymers showed high binding affinity toward BHb and the imprinting factor (α) reached 2.12. The specificity of the BHb recognition was evaluated with competitive experiments, indicating the imprinted polymers have a higher selectivity for the template BHb. The easy preparation protocol and good protein recognition properties made the approach an attractive solution to depletion of high‐abundance protein from bovine blood.     

Magnetic molecularly imprinted polymers for recognition and enrichment of polysaccharides from seaweed

New magnetic molecularly imprinted polymers with two templates were fabricated for the recognition of polysaccharides (fucoidan and alginic acid) from seaweed by magnetic solid‐phase extraction, and the materials were modified by seven types of deep eutectic solvents. It was found that the deep eutectic solvents magnetic molecularly imprinted polymers showed stronger recognition and higher recoveries for fucoidan and alginic acid than magnetic molecularly imprinted polymers, and the deep eutectic solvents‐4‐magnetic molecularly imprinted polymers had the best effects. The practical recovery of the two polysaccharides (fucoidan and alginic acid) purified with deep eutectic solvents‐4‐magnetic molecular imprinted polymers in seaweed under the optimal conditions were 89.87, and 92.0%, respectively, and the actual amounts extracted were 20.6 and 18.7 μg/g, respectively. To sum up, the developed method proved to be a novel and promising method for the recognition of complex polysaccharide samples from seaweed.     

Signaling molecularly imprinted polymers: molecular recognition-based sensing materials

Molecular imprinting is a template polymerization technique that can easily provide synthetic polymers capable of molecular recognition for given target molecules. In addition to their highly specific recognition ability, we are attempting to introduce signaling functions to molecularly imprinted polymers, enabling them to respond according to specific binding events. Some of our work regarding such signaling molecularly imprinted polymers is presented here, including molecularly imprinted polymers that induce spectral shifts of target compounds because of binding. Such compounds include hydrogen-bonding-based fluorescent imprinted polymers and metalloporphyrin-based signaling molecularly imprinted polymers.     

Epitope Imprinting of Phospholipids by Oriented Assembly at the Oil/Water Interface for the Selective Recognition of Plasma Membranes

Phospholipids, as fundamental building blocks of the cell membrane, play important roles for molecule transportation, cell recognition, etc. However, due to the structural diversity and amphipathic nature, there are few methods for the specific recognition of lipids as compared to other biomolecules such as proteins and glycans. Herein, we developed a molecular imprinting strategy for controllable imprinting toward the polar head of phospholipid exposed on the surface of cellular membranes for recognition. Phosphatidylserine, as unique lipid on the outer membrane leaflet of exosome and also hallmark for cell apoptosis, was imprinted with the developed method. The phosphatidylserine imprinted materials showed high efficiency and specific targeting capability not only for apoptotic cell imaging but also for the isolation of exosomes. Collectively, the synthesized molecularly imprinted materials have great potential for selective plasma membrane recognition for targeted drug delivery and biomarker discovery.     

Magnetic deep eutectic solvents molecularly imprinted polymers for the selective recognition and separation of protein

A novel and facile magnetic deep eutectic solvents (DES) molecularly imprinted polymers (MIPs) for the selective recognition and separation of Bovine hemoglobin (BHb) was prepared. The new-type DES was adopted as the functional monomer which would bring molecular imprinted technology to a new direction. The amounts of DES were optimized. The obtained magnetic DES-MIPs were characterized with fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), dynamic light scattering (DLS), elemental analysis and vibrating sample magnetometer (VSM). The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism. The maximum adsorption capability (Q_max) and dissociation constant (K_L) were analyzed by Langmuir isotherms (R² = 0.9983) and the value were estimated to be 175.44 mg/g and 0.035 mg/mL for the imprinted particles. And the imprinted particles showed a high imprinting factor of 4.77. In addition, the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples. Last but not least, the combination of deep eutectic solvents and molecular imprinted technology in this paper provides a new perspective for the recognition and separation of proteins.     

Preparation and characterization of molecularly imprinted silica monolith for screening sulfamethazine

In this work, a novel approach of preparing molecularly imprinted film‐derivatized silica monolith materials was developed by a two‐step procedure. The silica monolithic support was first prepared by the sol–gel method with tetramethoxysilane as the precursor. Subsequently, vinyl groups were introduced onto the surface of silica monolith by immobilization of γ‐methacryloxypropyltrimethoxysilane. The prepolymerization mixtures, consisting of methacrylic acid as a functional monomer, ethylene dimethacrylate as a crosslinker, sulfamethazine as a template molecule and an ionic liquid as porogen, were injected into the silica monolith immobilized vinyl groups to form the molecularly imprinted films on the surface of the vinyl functionalized silica monolith. The monolithic materials were characterized by SEM, Fourier transform IR and solid‐state reflection UV spectra. The resulted imprinted materials were evaluated under CEC and HPLC mode. The results indicated that there were enough recognition sites on the surface of the imprinted film‐derivatized monolithic materials for selectively recognizing sulfamethazine from the sulfonamide mixture. Ionic liquids, which was utilized as the porogens, could improve the flow‐through property and the imprinting effect of the molecularly imprinted film‐functionalized silica monolithic materials.     

Imprinted polymers-tailor-made mimics of antibodies and receptors

The technique of molecular imprinting allows the formation of specific recognition sites in synthetic polymers through the use of templates or imprint molecules. These recognition sites mimic the binding sites of antibodies and other biological receptor molecules. Molecularly imprinted polymers can therefore be used in applications relying on specific molecular binding events. The stability, ease of preparation and low cost of these materials make them particularly attractive. This review focuses on recent developments and advances in the field of molecularly imprinted materials, with special emphasis on applications in immunoassays and sensors recently developed by our group and by others.