Creatinine sensor based on a molecularly imprinted polymer-modified hanging mercury drop electrode

Molecularly imprinted polymers (MIP) have been elucidated to work as artificial receptors. In our present study, a MIP was applied as a molecular recognition element to a chemical sensor. We have constructed a creatinine sensor based on a MIP layer selective for creatinine and its differential pulse, cathodic stripping voltammetric detection (DPCSV) on a hanging mercury drop electrode (HMDE). The creatinine sensor was fabricated by the drop coating of dimethylformamide (DMF) solution of a creatinine-imprinted polymer onto the surface of HMDE. The modified-HMDE, preanodised in neutral medium at +0.4 V versus Ag/AgCl for 120 s, exhibited a marked enhancement in DPCSV current in comparison to the less anodised (≤+0.3 V) HMDE. The creatinine was preconcentrated and instantaneously oxidised in MIP layer giving DPCSV response in the concentration range of 0.0025-84.0 μg mL⁻¹ [detection limit (3σ) 1.49 ng mL⁻¹]. The sensor was found to be highly selective for creatinine without any response of interferents viz., NaCl, urea, creatine, glucose, phenylalanine, tyrosine, histidine and cytosine. The non-imprinted polymer-modified electrode did not show linear response to creatinine. The imprinting factor as high as 9.4 implies that the imprinted polymer exclusively acts as a recognition element of creatinine sensor. The proposed procedure can be used to determine creatinine in human blood serum without any preliminary treatment of the sample in an accurate, rapid and simple way.     

分子印迹聚合物传感器的研究与发展

综述了分子印迹聚合物的历史发展、制备方法、聚合体系的选择、性能表征及作用机理。主要介绍了其作为传感器敏感膜方面的应用,并对需解决的问题提出了建议。     

基于衣康酸配体构筑的两个锌配合物的合成、结构和荧光性质

通过水热法合成了两种锌配位聚合物{[Zn(ic)(bip)]·2H₂O}n (1)和[Zn(ic)(bpe)]n (2)(H₂ic=衣康酸,bip=3,5-二(1-咪唑基)吡啶,bpe=1,2-二(4-吡啶基)乙烯),并通过X射线单晶衍射和元素分析对其结构进行了表征.配合物1和2均为含有一维金属-羧酸链的二维(4,4)格子层结构.此外,对它们的热重、粉末X射线衍射和固体荧光性能进行了考察.与配体bip相比,1的发射光谱发生了明显的蓝移(~78 nm),可能归因于配体到金属的电荷转移;2显示与游离的bpe配体相似的荧光性质,轻微的红移可能是因为与金属离子之间的配位作用导致的.     

4-(2-(4-咪唑)苯乙烯基)吡啶和三种芳香二羧酸的Cd(Ⅱ)配位聚合物的合成、结构及荧光性质

以4-（2-（4-咪唑）苯乙烯基）吡啶（ISPE）为配体,分别与间苯二甲酸（1,3-H₂BDC）、4,4′-联苯二甲酸（4,4′-H₂BPDC）和4,4′-二苯乙烯二甲酸（4,4′-H₂STDC）及过渡金属盐Cd（NO₃）₂·4H₂O通过溶剂热自组装形成了3种配位聚合物晶体{[Cd₂（ISPE）₂（1,3-BDC）₂]·DMF}_n （1）、[Cd（ISPE）（4,4′-BPDC）]_n （2）和[Cd（ISPE）₂（4,4′-STDC）（H₂O）₂]_n （3）。并用单晶X射线衍射、PXRD、红外光谱、元素分析、热重等对其进行了表征。单晶解析结果表明：配位聚合物1是二维层状网格结构,配位聚合物2是一个六重穿插的类金刚烷三维网格结构,配位聚合物3是由一维网格结构通过氢键和分子间作用力堆积形成的三维网格结构。另外还研究了它们的室温固态荧光性能。     

Molecularly imprinted polymers on the surface of silica microspheres via sol‐gel method for the selective extraction of streptomycin in aqueous samples

Streptomycin‐imprinted silica microspheres were prepared by combining a surface molecular‐imprinting technique with the sol‐gel method. A mixture of tetrahydrofuran, ethanol, and water (6:1:1, v/v/v) was selected as dispersing solvent while 3‐aminopropyltriethoxysilane and triethoxyphenylsilane acted as functional monomers, and tetraethyl orthosilicate as a cross‐linker. Characterization of the molecularly imprinted polymers was conducted using scanning electron microscope and dynamic binding experiments. As compared to the nonimprinted polymers, the imprinted polymers exhibited a higher degree of saturated adsorption volume up to 26.3 mg/g, and better selectivity even in an aqueous solution with interfering compounds, including dihydrostreptomycin, neomycin, and tetracycline. The adsorption ability and selectivity were observed to be influenced by the mole ratio of 3‐aminopropyltriethoxysilane and triethoxyphenylsilane. Feasibility of the polymers to be used for actual application was also evaluated with spiked samples, indicating great potential for large‐scale applications. Moreover, the streptomycin‐imprinted polymers can be repeatedly used for 12 cycles without losing original performance, which is beneficial for commercial use.     

分散固相萃取-超快速液相色谱-串联质谱法测定牛蛙全血中6种酚类环境雌激素

建立了一种快速、灵敏、准确的同时测定牛蛙全血中双酚A、己烯雌酚、己二烯雌酚、己烷雌酚、4-叔辛基酚和4-壬基酚等6种酚类环境雌激素的分散固相萃取-超快速液相色谱-串联质谱(dSPE-UFLC-MS/MS)分析方法。牛蛙全血样品经含0.1%(v/v)甲酸的甲醇溶液沉淀蛋白后,利用自制的氨基功能化Fe3O4磁性高分子复合微粒(EDA-MPs)作为dSPE吸附剂进行净化,着重考察了沉淀剂、吸附净化时间、吸附剂用量等因素对6种酚类环境雌激素回收率的影响。采用Shim-pack XR-ODSII(100 mm×2.0 mm, 2.2 μm)反相液相色谱柱进行分离,在电喷雾离子源(ESI)负离子多反应监测(MRM)模式下进行检测。结果表明: 6种酚类环境雌激素在0.5～100.0 μg/L范围内具有良好的线性关系(r2≥0.9996),方法的定量限(信噪比大于10)为0.075～0.40 μg/L,方法的精密度为0.6%～6.3%,空白样品中3个不同水平的添加回收率为95.0%～110.0%。本方法适用于牛蛙全血中6种酚类环境雌激素的同时测定。     

壬基酚表面印迹聚合物微球的合成及分子识别特性

采用表面分子印迹技术,在二氧化硅微粒表面通过乙烯基三甲氧基硅烷接枝,以壬基酚(NP)为模板、α-甲基丙烯酸为功能单体制备了壬基酚印迹聚合物。扫描电镜及比表面分析仪测试结果表明制备的印迹聚合物呈均匀分散的微球,具有较大的比表面积。采用红外光谱表征印迹聚合物微球制备过程中的化学结构变化情况,并用平衡吸附法研究了聚合物对NP的结合性能与分子识别特性。研究结果表明,聚合物对壬基酚具有良好的结合亲和性,最大结合量可达184.6 mg/g。印迹聚合物对NP的吸附量高于其结构类似物对特辛基酚和双酚A的吸附量,表现出较高的选择性识别能力。     

配位印迹聚合物在分析化学中的应用进展

分子印迹聚合物(MIP)是一种对目标分子(模板分子)具有选择性结合能力的聚合物.配位印迹聚合物(CIP)是基于金属离子与功能单体、模板分子间配位作用的分子印迹聚合物,既沿袭了MIP的优点,又具有适用于极性环境等优点,在食品、环境、生物、医药等领域目标物的识别中有良好的应用潜力.本文介绍了CIP的原理和特点,综述了CIP在分析化学中的应用进展,展望了CIP的发展前景.