沉淀聚合法制备三聚氰胺分子印迹聚合物微球

以三聚氰胺为模板分子,以甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,在乙腈-乙二醇(20∶1,V/V)混合溶剂中沉淀聚合制备了分子印迹聚合物微球.利用1H-NMR和紫外光谱方法研究了模板与功能单体相互作用情况.结果表明,三聚氰胺与甲基丙烯酸(MAA)分子通过协同氢键作用形成1∶2型氢键配合物.利用扫描电镜和红外光谱对聚合物微球的结构进行了表征.结果表明,印迹聚合物近似圆球形,粒径约为400～500 nm,且大于非印迹聚合物微球,表面存在大量的结合位点.通过静态平衡吸附实验研究了聚合物微球对模板分子的结合能力,印迹聚合物微球在4 h后逐渐达到吸附平衡,Scatchard分析表明,印迹聚合物微球主要存在两类不同的结合位点,最大表观结合量(Qmax)和平衡离解常数(Kd)分别为Qmax1=22.97μmol/g,Kd1=0.14×10-3 mol/L;Qmax2=157.65μmol/g,Kd2=2.55×10-3 mol/L,计算得出表观印迹效率和有效印迹效率分别为68%和58%.此方法合成的印迹聚合物微球对三聚氰胺有较好的结合性能,可应用于三聚氰胺的分离检测.     

茶碱分子表面印迹微球的制备及其体外释药性能

通过分子表面印迹技术,采用铈盐-羟基氧化还原引发体系,以交联聚乙烯醇(CPVA)微球为基质、对苯乙烯磺酸钠(SSS)为功能单体、茶碱(TP)为模板药物分子、N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,制备了TP分子表面印迹微球MIP-PSSS/CPVA。采用红外光谱测定其结构,扫描电镜观察其表面形貌,静态法考察印迹微球MIP-PSSS/CPVA对TP的结合性能及载药印迹微球的体外释药行为。结果表明:TP分子表面印迹微球MIP-PSSS/CPVA对TP具有较高的识别选择性和结合亲合性,当pH=1时,微球对TP的结合容量达到92mg/g。该印迹微球在模拟胃液中基本不释药;在模拟小肠液中的第2~6h,累积释放率仅为21%;而在模拟结肠液中突释,之后持续缓慢地释放,表现出优良的pH敏感和时滞双重型结肠定位释药特性。     

核-壳型苏丹红Ⅰ印迹聚合物微球制备及应用研究

以苏丹红Ⅰ为模板分子,苯基-三甲氧基硅烷(PTMOS)为功能单体,乙二醇二甲基丙烯酸酯(EGD-MA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用表面分子印迹技术,在自制的SiO2微球表面成功合成了对苏丹红Ⅰ具有良好选择识别性能的核-壳型印迹聚合物。采用红外光谱和扫描电子显微镜对分子印迹微球进行表征,结果表明该印迹聚合材料壳层厚度约为150 nm;采用静态吸附实验研究印迹材料对模板聚合物的吸附性能和选择特性,结果表明以PTMOS为功能单体的印迹聚合物对苏丹红Ⅰ具有优异的选择吸附性,其分离选择因子为2.62。在吸附过程中,模板分子苏丹红Ⅰ与印迹聚合物形成2种结合位点,2种结合位点的解离常数分别为2.30、10.78 mmol/L,最大表观结合量分别为27.40、128.53μmol/g。将该印迹聚合物作为固相萃取材料,对样品进行固相萃取,结合液相色谱技术成功用于辣椒油中苏丹红Ⅰ的测定。     

分子印迹滤过型净化柱净化/分子荧光光谱法测定花生根中白藜芦醇

以白藜芦醇(RES)为模板分子,凹凸棒土(ATP)为载体,β-环糊精(β-CD)和甲基丙烯酸(MAA)为双功能单体,采用表面分子印迹技术制备了白藜芦醇分子印迹聚合物(MIPs)。将制得的分子印迹聚合物作为吸附剂填料,填充滤过型净化柱,用于富集净化花生根中的白藜芦醇,建立了分子印迹滤过型净化柱净化/分子荧光光谱测定花生根中白藜芦醇的新方法。在最优化条件下,分子印迹聚合物对RES具有良好的选择性,最大吸附容量可达12.78 mg/g,白藜芦醇在0.1~100μg/m L浓度范围内呈良好的线性关系(r=0.999 7),方法检出限为0.048μg/L,样品加标回收率为86.2%~102.1%,相对标准偏差(RSD)为3.5%~5.8%。该方法高效、快速、选择性好,可用于白藜芦醇的快速检测。     

核-壳型厚朴酚印迹聚合物的制备及性能研究

以表面修饰功能基团的SiO2微球为基体,以厚朴酚为模板分子,丙烯酰胺为功能单体,丙烯酸乙二醇二甲酯为交联剂,在SiO2微球表面制备对厚朴酚具有较好选择识别能力的核-壳型印迹聚合物.采用红外光谱及扫描电镜等技术表征聚合物的结构及形态.结果表明,该印迹聚合物表面成功制备了壳层厚度约为200nm的均匀印迹层.通过静态吸附、Scatchard分析法以及竞争吸附实验研究了该聚合物的吸附性能和选择性,结果表明,它对厚朴酚形成均一结合位点,离解常数为0.19mg/mL.     

葡萄球菌肠毒素B分子印迹聚合物的制备及其与蛋白质的结合性能

以葡萄球菌肠毒素B(SEB)蛋白为模板分子,以聚苯乙烯微球为基质,采用表面分子印迹法制备了SEB分子印迹聚合物.利用平衡吸附试验分析了SEB聚合物对目标蛋白的吸附能力及对类似底物的选择性;分析了该聚合物的吸附动力学,并利用扫描电镜观察了其形貌特征和颗粒尺寸.结果表明,经Scatchard模型分析求得的标题聚合物的最大表观结合量Qmax为3.23mg/g;所制备的SEB分子印迹聚合物呈微球形,粒径约为1²μm,对SEB蛋白具有较好的吸附性和特异选择性.     

分子印迹固相萃取/高效液相色谱法检测黄瓜中灭蝇胺

以灭蝇胺为模板分子,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,甲苯和异辛烷为二元致孔剂,采用低温光引发、本体聚合法制备了灭蝇胺的分子印迹聚合物.通过平衡吸附实验、扫描电镜、红外光谱以及压汞仪等多种手段对制备的印迹和非印迹聚合物进行了测定与表征,结果表明所制备的印迹聚合物对模板分子具有明显的特异性吸附作用.Scatchard分析证明灭蝇胺分子印迹聚合物对灭蝇胺分子的吸附存在两类不同结合位点,最大表观结合量(Qmax)和平衡解离常数(Kd)分别为Qmax1=1.19μmol/g,Kd1=1.31 μmol/L;Qmax2 =2.46 μmol/g,Kd2=4.84 μmol/L.用该聚合物制备的灭蝇胺分子印迹固相萃取柱处理样品,结合高效液相色谱法可快速有效地检测黄瓜样品中的灭蝇胺,线性范围为0.1～10 mg/L(r =0.9991),检出限(S/N=3)为0.05 mg/L.该方法快速简便,效果优于商品化的固相萃取柱.     

具有高选择性吸附的表面分子印迹磁性纤维素微球的制备与性能

以纤维素和纳米Fe₃O₄为原料制得磁性纤维素微球, 在纤维素微球表面选择合适的模板分子, 以甲基丙烯酸、 丙烯酰胺和N,N'-亚甲基双丙烯酰胺为功能单体, 采用水溶液聚合法制得表面分子印迹磁性纤维素微球. 采用傅里叶变换红外光谱(FTIR)、 X射线衍射(XRD)和振动样品磁强计(VSM)等表征了分子印迹聚合物微球的结构. 以罗丹明B(RhB)为模板分子, 通过吸附动力学与吸附热力学实验研究了表面分子印迹磁性纤维素微球对RhB的吸附性能, 结果表明, 制备的表面分子印迹磁性纤维素微球对罗丹明B具有特异性识别作用, 饱和吸附量达到0.542 mg/mg, 吸附平衡时间为10 h左右. 表面分子印迹磁性纤维素微球大大降低了对吸附环境的依赖, 并可重复利用.     

基于金属卟啉的甲基磷酸二甲酯分子印迹聚合物微球的合成及性能

合成了分别以5-(4-甲基丙烯酰氧苯基)-10,15,20-三苯基锌卟啉(ZnMOTPP)和5-(4-甲基丙烯酰氧苯基)-10,15,20-三苯基钆卟啉(GdMOTPP)为功能单体, 甲基丙烯酸(MAA)为辅助功能单体的甲基磷酸二甲酯(DMMP)分子印迹聚合物微球. 扫描电子显微镜(SEM)表征结果表明, 微球平均粒径为50～100 μm, 粒度均匀. 与甲基丙烯酸作为功能单体的分子印迹聚合物微球的吸附性能和特异性进行对比发现, ZnMOTPP分子印迹微球的吸附性能优于 GdMOTPP分子印迹微球, 金属卟啉分子印迹微球的吸附性能优于仅以甲基丙烯酸作为功能单体的分子印迹微球, 并且微球对其印迹分子DMMP具有特异性吸附. Scatchard分析表明, DMMP分子印迹空穴中只存在一类结合位点, MIPMs-Zn+MAA的最大吸附量Q_max=148 μmol/g, MIPMs-Gd+MAA的Q_max=78.9 μmol/g, MIPMs-MAA的Q_max=13.57 μmol/g.     

5-氟尿嘧啶分子表面印迹微球MIP-PSSS/CPVA的制备及其体外结肠定位释药特性研究

以对苯乙烯磺酸钠(SSS)为功能单体, 以N,N'-亚甲基双丙烯酰胺(MBA)为交联剂, 采用铈盐-羟基氧化还原引发体系, 在交联聚乙烯醇(CPVA)微球表面实施了5-氟尿嘧啶(5-FU)分子的表面印迹, 在微球CPVA表面形成印迹聚合物(MIP)层, 即制备了5-FU分子印迹微球MIP-PSSS/CPVA. 采用红外光谱(FTIR)和扫描电子显微镜(SEM)法, 对印迹微球进行了表征. 重点考察分析了印迹微球对5-氟尿嘧啶(5-FU)的结合(载药)性能与结合机理, 考察探索了载药微球在不同pH介质中的释放行为. 实验结果表明, 基于本体系特殊的羟基-铈盐表面引发体系, 可有效地实现5-FU分子的表面印迹, 在微球CPVA表面形成分布有大量5-FU分子印迹空穴的聚合物层. 在酸性介质中, 受强静电相互作用的驱动, 印迹微球MIP-PSSS/CPVA对5-FU分子表现出很强的结合能力, 结合容量达110 mg/g, 可实现有效载药. 载药微球的释药行为既具有强烈的pH依赖性, 又具有时滞性: 在模拟胃液中(pH＝1), 基本不释药; 在模拟小肠液中(pH＝6.8), 释药量很小; 在模拟结肠液中(pH＝7.4), 则发生突释, 表现出高效的结肠定位释放行为.     

Preparation of surface molecularly imprinted Ru-complex catalysts for asymmetric transfer hydrogenation in water media

Molecularly imprinted Ru-complex catalysts acting in water were prepared on a SiO(2) surface by molecular imprinting of a SiO(2)-supported Ru-complex using organic polymers as surface matrix overlayers. (R)-1-(o-fluorophenyl)ethanol, which is one of the hydrogenated products of o-fluoroacetophenone, was imprinted on the supported Ru-complex as a template, and an active Ru-complex with a shape-selective reaction space (molecularly imprinted cavity) was prepared inside the wall of the hydrophobic organic polymer matrix overlayers. Structures of the SiO(2)-supported and molecularly imprinted Ru catalysts were characterized by means of solid-state NMR, XPS, XRF, ICP, UV/vis, XAFS, TGA, and SEM. The molecularly imprinted Ru catalysts exhibited fine shape selectivity and enantioselectivity for the asymmetric transfer hydrogenation of o-fluoroacetophenone and its derivatives.     

Preparation and catalytic performances of a molecularly imprinted Ru-complex catalyst with an NH2 binding site on a SiO2 surface

A catalyst surface with an active metal site, a shape-selective reaction space, and an NH(2) binding site for o-fluorobenzophenone was designed and prepared by the molecular imprinting of a supported metal complex on a SiO(2) surface. A ligand of a SiO(2)-supported Ru complex that has a similar shape to the product of o-fluorobenzophenone hydrogenation was used as a template. An NH(2) binding site for o-fluorobenzophenone was spatially arranged on the wall of a molecularly imprinted cavity with a similar shape to the template. The structures of the SiO(2)-supported and molecularly imprinted Ru catalysts were characterized in a step-by-step manner by means of solid-state magic angle spinning (MAS) NMR, XPS, UV/Vis, N(2) adsorption, XRF, and Ru K-edge EXAFS. The molecularly imprinted Ru catalyst exhibited excellent shape selectivity for the transfer hydrogenation of benzophenone derivatives. It was found that the NH(2) binding site on the wall of the molecularly imprinted cavity enhanced the adsorption of o-fluorobenzophenone, of which the reduction product was imprinted, whereas there was no positive effect in the case of o-methylbenzophenone, which cannot interact with the NH(2) binding site through hydrogen bonding.     

新型多壁碳纳米管/白藜芦醇印迹溶胶-凝胶层层组装电化学传感器研究

采用电化学沉积方法将印迹溶胶-凝胶膜沉积到功能化碳纳米管(MWNT-COOH)修饰的碳电极表面,成功研制一种新型多壁碳纳米管/白藜芦醇印迹溶胶-凝胶电化学传感器.采用扫描电镜(SEM),循环伏安法(CV),方波伏安法(SWV)和计时电流法(i-t)详细考察该印迹溶胶-凝胶膜的形态和电化学性能.结果表明该传感器对白藜芦醇具有较高的选择性和亲和性.与无多壁碳纳米管修饰的印迹传感器比较,MWNT层修饰的印迹传感器电流响应信号明显提高.白藜芦醇与印迹溶胶-凝胶膜的特异性结合使该传感器的电流发生变化,电流变化与白藜芦醇浓度在5.0×10-7～8.0×10-5mol?L-1范围内呈良好线性关系,检测限为5.1×10-8mol?L-1,该传感器成功应用于葡萄酒中白藜芦醇含量的检测.     

分子印迹在线富集-化学发光法测定葡萄酒和虎杖提取物中的白藜芦醇

制备了白藜芦醇的分子印迹聚合物,用聚四氟乙烯管作为微固相萃取柱,连接在流动注射系统的八通阀上,对白藜芦醇进行富集和分离;经甲醇和乙酸混合洗脱液(9:1,V/V)在线洗脱后与酸性KMnO4发生化学发光反应.测定白藜芦醇的线性范围2.5×10-7～6.1×10-5g/mL,方法的检出限为(3σ)8×10-8g/mL,11次...     

Preparation of Surface Molecularly Imprinted Poly(dopamine) Film for 4-Hydroxybenzoic Acid (4-BA) Recognition by One-Step Method

In this paper, we present a one-step aqueous self-polymerization strategy to prepare surface molecularly imprinted poly(dopamine) (PDA) film. The method is simple and convenient compared with the “template-guided” surface molecularly imprinted synthesis method and the layer-by-layer self-assembly and the surface-grafted molecularly imprinted synthesis methods. The molecularly imprinted PDA films could selectively bind the template molecules (4-Hydroxybenzoic acid as a model), and bisphenol A (BPA) imprinted PDA films were also investigated. Meanwhile, the 2-dimension imprinted film material was used very conveniently.     

Flow injection chemiluminescence sensor using core-shell molecularly imprinted polymers as recognition element for determination of dapsone

This paper reports the preparation of dapsone (DDS) imprinted polymer layer-coated silica submicron particles (SiO(2)) combined with chemiluminescence (CL) toward analysis of tracing DDS in practical samples. To induce the selective occurrence of surface polymerization, the amino groups were first grafted at the surface of SiO(2) by the (3-aminopropyl)triethoxysilane (APTES). The molecularly imprinted polymers (MIP) were coated at the surface of modified SiO(2) by the graft copolymerization. After the removal of templates, recognition sites of DDS were exposed in the polymer layers. The DDS-imprinted products were characterized by FT-IR, SEM, TEM, dynamic adsorption, and static adsorption tests. The proximity between the thickness of MIP layer and the spatial size of DDS indicated that the imprinted sites almost situated at the surface of MIP, leading to rapid adsorption saturation within 90 min. The apparent maximum binding amount of MIP toward DDS was evaluated as 14.98 mg·g(-1), which was much higher than that of non-molecularly imprinted polymers. The CL sensor provided a wide linear range for DDS within 1.0 × 10(-6) to 1.0 × 10(-4) mol·L(-1) with a detection limit of 5.27 × 10(-7) mol·L(-1) and the relative standard deviation of 1.8 % (n = 11) by determinations of 5.0 × 10(-6) mol·L(-1) DDS. This method was applied to determine DDS in urine samples and satisfactory results were obtained.     

Uniform-sized molecularly imprinted polymer for (S)-naproxen selectively modified with hydrophilic external layer.

A uniform-sized molecularly imprinted polymer (MIP) for (S)-naproxen selectively modified with hydrophilic external layer has been prepared. First, the molecularly imprinted polymer for (S)-naproxen was prepared using 4-vinylpyridine and ethylene glycol dimethacrylate (EDMA) as a functional monomer and cross-linker, respectively, by a multi-step swelling and thermal polymerization method. Next, a 1:1 mixture of glycerol monomethacrylate (GMMA) and glycerol dimethacrylate (GDMA) was used for hydrophilic surface modification, and it was added directly to the molecularly imprinted polymer for (S)-naproxen 4 h after the start of molecular imprinting. The retention factors of all solutes tested were decreased with the surface modified molecularly imprinted polymer, compared with the unmodified molecularly imprinted polymer. However, chiral recognition of racemic naproxen was attained with the surface modified molecularly imprinted polymer as well as the unmodified molecularly imprinted polymer. Further, bovine serum albumin was completely recovered from the surface modified molecularly imprinted polymer. These results revealed that the chiral recognition sites of (S)-naproxen remained unchanged with hydrophilic surface modification, and that the molecularly imprinted polymer for (S)-naproxen was selectively modified with hydrophilic external layer. Preliminary results reveal that the surface modified molecularly imprinted polymer could be applicable to direct serum injection assays of (S)-naproxen.     

烟酸分子印迹复合膜的制备及其分离性能研究

以聚偏氟乙烯微孔滤膜为支撑膜,烟酸为模板分子,用紫外光引发表面修饰聚合制备了微孔滤膜支撑-烟酸分子印迹复合膜.电镜扫描对该印迹复合膜进行了表面形态表征.Scatchard分析表明,在所研究的浓度范围内分子印迹复合膜中存在等价的结合位点,结合位点的平衡离解常数Kd为5.55×10-2mmol·L-1.底物的结合和渗透选择性实验表明,分子印迹复合膜对烟酸有较好的结合性能,结合量是6.10μmol·g-1.与其结构类似的化合物烟酰胺相比,分子印迹复合膜对模板分子展示了更好的选择性及高度的识别能力.     

Innovative method for the enrichment of high‐polarity bioactive molecules present at low concentrations in complex matrices

Ginsenoside Rg1 is a valuable bioactive molecule but its high polarity and low concentration in complex mixtures makes it a challenge to separate Ginsenoside Rg1 from other saponins with similar structures, resulting in low extraction efficiency. The successful development of effective Rg1 molecularly imprinted polymers that exhibit high selectivity and adsorption may offer an improved method for the enrichment of active compounds. In this work, molecularly imprinted polymers were prepared with two different methods, precipitation polymerization or surface imprinted polymerization. Comparison of the adsorption abilities showed higher adsorption of the surface molecularly imprinted polymers prepared by surface imprinted polymerization, 46.80 mg/g, compared to the 27.74 mg/g observed for the molecularly imprinted polymers prepared by precipitation polymerization. Therefore, for higher adsorption of the highly polar Rg1, surface imprinted polymerization is a superior technique to make Rg1 molecularly imprinted polymers. The prepared surface molecularly imprinted polymers were tested as a solid‐phase extraction column to directionally enrich Rg1 and its analogues from ginseng tea and total ginseng extracts. The column with surface molecularly imprinted polymers showed higher enrichment efficiency and better selectivity than a C₁₈ solid‐phase extraction column. Overall, a new, innovative method was developed to efficiently enrich high‐polarity bioactive molecules present at low concentrations in complex matrices.