零流电位法对4-氨基联苯的检测

以铅笔芯电极(PGE)为工作电极,铂电极为对电极,饱和甘汞电极为参比电极,在含4. 0×10-3mol/L丙烯酸、1. 0×10-3mol/L 4-氨基联苯(4-ABP)的磷酸盐缓冲溶液(PBS,p H 7. 17)中,采用循环伏安法以0. 1 V·s-1在-1. 6～1. 6 V电位范围循环扫描16圈,经超声洗脱6 min后制得4-氨基联苯印迹聚合物修饰电极(4-ABP-MIP/PGE)。零流电位法下,在4-ABP浓度0. 005～50μmol/L范围内,4-ABP-MIP/PGE的零流电位EZCP与4-ABP浓度的对数呈线性关系,检出限为1. 07 nmol/L。将该传感器用于实际样品中4-ABP的检测,平均回收率为96. 0%～102%。     

联苯胺分子印迹聚合物零流电位法传感器的制备及其应用

考察了在石墨烯修饰的铅笔芯电极( G-PEC)表面制备联苯胺分子印迹聚合物( BZ-MIP)的电聚合参数以及模板分子从印迹聚合物中去除的洗脱时间对BZ-MIP与BZ结合前后零流电位响应差值的影响,优化了最佳制备条件;计算出联苯胺及与其结构相近的4-氨基偶氮苯、4-氯苯胺、4-氨基联苯和单偶氮染料胭脂红在BZ-MIP上的印迹容量分别为0.632,0.1123,0.1123,0.0847和0.0725。实验结果表明,本方法制备的BZ-MIP对联苯胺特异识别性和选择性良好,其它物质不干扰模板分子与印迹聚合物印迹位点的结合。在联苯胺4伊10-8~1伊10-5 mol/L浓度范围内,BZ-MIP与BZ结合前后的零流电位差与其浓度对数呈正比,检出限为1.89伊10-8 mol/L,基于此制备出检测联苯胺的BZ-MIP-G-PEC零流电位传感器。应用此传感器检测实际样品,回收率为95.7%~104.2%。     

零流电位法在酸碱滴定中的应用研究

探讨了零流电位法在酸碱滴定中的检测原理及应用,通过考察强碱滴定弱酸、强碱滴定强酸、强酸滴定弱碱以及强酸滴定强碱四种滴定体系,探明了零流电位法在酸碱滴定中的适用性。通过氢氧化钠滴定醋酸对本方法进行评价,实验结果表明:本法的相对误差为-0.4%,同一根电极的滴定值的相对标准偏差(RSD)为0.4%(n=5),同一根电极五天滴定值的RSD为0.6%,五根电极滴定值的RSD为0.5%。本方法具有较高的准确性、稳定性和重现性。     

一种基于PVC膜电极的电位式葡萄糖传感器的研制

以三庚基十二烷基碘代季铵盐为电活性物质的PVC膜电极, 对过氧化氢和六价钼的络合物具有良好的电位响应. 将葡萄糖氧化酶固定到PVC膜电极表面, 制备成电位式葡萄糖传感器. 在优化的实验条件下, 该传感器在葡萄糖浓度为2×10^－4～5×10^－3 mol/L范围内有线性响应, 检测下限为5×10^－5 mol/L. 另外该传感器具有较高的稳定性和良好的选择性, 抗坏血酸、尿酸和一些氨基酸未对测定产生干扰.     

测定甲胎蛋白的非标记电位型免疫传感器

免疫分析是最重要的生物化学分析方法之一，是根据抗体与抗原或半抗原之间的专一性反应建立的分析方法，具有高度的选择性和极低的检测下限．电化学免疫传感器就是将免疫分析技术与电化学传感器相结合的一种新的免疫分析方法，具有免疫反应的高选择性和电化学分析的高灵敏性．甲脂蛋白（AFP）是人血清中含有的一种微量蛋白质，正常人血清中的含量在20ug／L以下，多种肝病都会引起甲胎蛋白含量的显著增加．甲脂蛋白能作为一种抗原与抗甲脂蛋白抗体反应，利用多克隆抗体免疫测定的甲胎蛋白总量，是临床化学检验上的一项重要指标．Aizawa等报…     

电位型传感器嵌入式遥测系统的研制

研制了一种应用于电位型传感器的嵌入式遥测系统。系统由采样发送端、接收端和计算机组成。采样发送端包括电流放大器、∑-Δ型模数转换器、微控制器和无线数据传输模块,接收端包括无线数据传输模块、微控制器和协议转换器,接收端通过通用串行总线( USB)接口和计算机连接。嵌入式软件用C语言编写,控制信号的采集和传输;上位机软件用 LabVIEW编写,用于数据存储和显示。系统采集电压信号范围为±1.17 V。为验证该系统的精度和可靠性,应用本套系统和数字多用表对一组电位值进行了对照测试,并用自制的氢离子选择性电极进行了酸度变化响应测试。结果表明,本系统电位测量值可以精确到0.1 mV,且抗噪能力良好,pH响应测量的线性相关系数R2=0.998,变化曲线和商品化的电化学分析仪的结果一致。此系统硬件均由标准芯片组成,采样发送端尺寸为29 mm×14 mm×11 mm,可以用于电位型传感器的远程实时检测。     

甲胎蛋白光寻址电位式传感器的研究

研究了基于光寻址电位传感器(LAPS)的无标记甲胎蛋白免疫检测。采用共价交联的方法在光寻址电位传感器的敏感膜表面固定甲胎蛋白抗体,根据蛋白质分子特异性结合会引起膜电位变化进行检测;对度为400μg/L甲胎蛋白抗原的响应约为11mV;不同浓度的甲胎蛋白抗原的响应同浓度呈线性关系,线性相关系数为0．9996;各个芯片对不同浓度AFP膜电位响应的相对标准偏差小于6％。验证了采用光寻址电位传感器技术检测甲胎蛋白的可行性,为多参数蛋白质芯片的研究提供了理论和实验数据。     

Zero Current Potentiometry for Measuring the Interface Potential at the Electrode/Solution Interface. Theoretical and Experimental Study

A novel electrochemical approach has been proposed to measure the interface potential at the electrode/solution interface based on reconstructing the three‐electrode system of a potentiostat. In this work, the method was investigated both theoretically and experimentally. Mathematical expressions, describing current? potential characteristics, were derived. Zero current potential E_zcp was defined as the potential at which the current is zero based on linear sweep voltammetry, and was determined from the I? E curve to measure the interface potential. The experimental results obtained with the couples Fe(CN)₆^3?/Fe(CN)₆^4? and Co(NH₃)₆³⁺/Co(NH₃)₆²⁺ as examples agreed well with the theory. The proposed approach exhibits an excellent performance for measuring the interface potential due to the advantages of rapidity, high stability and accuracy.     

Interfacial Rheological Property and Rheokinetics of a Novel Photoreversible Micellar System

A new photorheologically reversible micelle composed of a polymerizable cationic surfactant N-cetyl dimethylallyl ammonium chloride (CDAAC) and trans-4-phenylazo benzoic acid (trans-ACA) was prepared. Exposing the CDAAC/trans-ACA (14 mM/10 mM) micellar system to the UV light (365 nm) resulted in a decrease in the relative viscosity, and in turn, the relative viscosity increases to its initial value when the micellar system was exposed to visible light (460 nm), which is caused by the photoisomerization of ACA. The interfacial tension and modulus of the micellar system change significantly after UV irradiation and show the reversible interfacial rheological properties when irradiated by visible light. Furthermore, for the first time the dynamic changing of the rheological properties, i.e., the decreasing of viscosity and viscoelasticity during the UV irradiation, has been studied and well described by a rheokinetics model.     

界面振荡现象

表面活性剂十二烷基三甲基溴化铵从水相向硝基乙烷相的迁移导致以界面振荡为特征的界面不稳定现象，基于界面吸附平衡对该现象的成因进行解析，得到了体现溶质界面吸附和扩散迁移的双因素关系式，可对界面振荡运动的成因及有关规律作出解释。     

A Novel Nitrite Amperometric Sensor and Its Application in Food Analysis

Brilliant cresyl blue (BCB), one of the phenoxazine dyes, was electropolymerized on the glassy carbon (GC) electrode. The resulting electroactive polymer film could provide more active sites for anodic oxidation of nitrite, based on which a novel nitrite sensor was developed. The optimized fabrication and sensing conditions were investigated. This sensor exhibited high sensitivity, low detection limit and simple operation toward the electrochemical oxidation of nitrite. It was successfully applied to the determination of nitrite in some food samples and the results were consistent with those obtained with the standard spectrophotometric procedure.     

一种新型一氧化氮电化学传感器

将一种自合成的水溶性聚对苯撑乙烯(PPV)衍生物电聚合到玻碳电极表面, 制得一种新型NO电化学传感器. 实验结果表明, 该传感器对NO具有灵敏的伏安响应, 相对裸玻碳电极两个氧化峰电位均负移达180 mV. 安培实验结果表明, NO的响应电流与其浓度在 1.8×10-7～1.0×10-4 mol/L范围内有良好的线性关系(r＝0.999 3), 检出限达到2.3×10-8 mol/L. 用旋转圆盘电极研究了NO在该传感器上的电化学行为, 并计算出NO在0.1 mol/L的磷酸盐生理缓冲溶液(PBS)中的扩散系数.     

一种新的基于折射率变化的光纤化学传感器

在光纤化学传感器中,基于样品折射率变化的传感器是其中的重要分支,并获得了广泛的实际应用^[1].根据敏感部件的不同可将其分为两大类:一类的敏感部件是裸光纤,这类传感器已用于检测苯、甲醇和丙酮^[2],测定血样中葡萄糖浓度^[3],鉴定燃油质量.     

Novel Cesium Membrane Sensor Based on a Cavitand

A PVC‐based membrane sensor was prepared for Cs⁺ ions, which was based on 7,11,15,28‐tetraiodo‐1,21,23,25‐tetramethyl‐2,20:3,19‐dimethano‐1H,21H,23H,25H‐bis[1,3]dioxocino[5,4‐i:5′,4′i′] benzo[1,2‐d:5,4‐d′]‐bis[1,3]benzodioxocin stereoisomer (cavitand). The proposed membrane electrode exhibits a linear dynamic range of 1.0 × 10^?;1–1.0 × 10^?;5M, with a Nernstian slope of 59.1 ± 0.3 mV per decade, and a detection limit of 5.0 × 10^?;6 M. It has a very fast response time of <10 s and can be used for at least eight weeks without any considerable divergence in its potentials. The best sensor performance was obtained with a membrane containing 30% PVC, 62% dibutylphthalate (DBP), 6% cavitand, and 2% potassium tetrakis(p‐chlorophenyl) borate (KTpClPB). The sensor could be used in a pH range of 4.3–9.5.     

界面不稳定现象与相间迁移

The interfacial instability due to the transfer of the 1-butanol from water to oil in two systems of 1-butanol oil/water has been studied. The dynamic characteristics of the phenomenon are investigated by analysing the motion of an oil lens deposited at the surface of the aqueous solution of 1-butanol. The interfacial adsorption kinetics based on diffusion-controlled transfer is analysed. It is found that the linear relation between the frequence of the oscillatory motion of the lens and t1/2 is a characteristic relation. The type of the solute transfer in the interfacial instability is discussed by comparing experimental results with the linear characteristics.     

界面不稳定现象与相间迁移

包含有流动界面的多相体系中的溶质相间迁移在一定条件下可导致表现为界面变形、界面流和多种形式界面运动的不稳定现象．该现象的直接驱动力是界面局部区域出现的张力梯度，表面活性物质在该现象中起重要作用[1，2]．溶质相间迁移通常可考虑为三步：（1）溶质在原所在相内部向