导电聚合物电极同时测定痕量铜、铅、镉、锌

使用一种新型导电聚合物电极作为工作电极,采用阳极溶出伏安法通过同位镀铋对导电聚合物电极进行修饰,实现了痕量铜、铅、镉、锌的同时测定.比较了导电聚合物电极和丝网印刷碳电极的性能,研究了预富集时间和不同介质对重金属离子测定的影响规律.结果表明:铜、铅、镉、锌在铋膜修饰的导电聚合物电极上分别在0.05 V、-0.55 V、-0.80 V、-1.10 V产生灵敏的电位溶出峰,峰高与离子浓度线性相关,最低检测限分别可达到0.5 μg/L、1 μg/L、1 μg/L和0.5 μg/L.在检测重金属离子方面,导电聚合物电极比丝网印刷碳电极更加灵敏和稳定,为一次性电化学传感器的发展提供了良好的基础.     

非汞电极溶出伏安法及其生物分析应用新进展

该文简要综述了非汞电极(铋膜电极、锑膜电极、欠电位沉积相关的贵金属电极、其它惰性电极)阳极溶出伏安法测定重金属离子及其生物分析应用的研究新进展,引用文献45篇.     

传感器技术在金属检测中的新发展

重金属污染是环境中的一项重要污染,传感器技术在重金属检测中发挥着重要作用.主要从离子选择性电极、光纤传感器和生物传感器以及电极矩阵4个方面对传感器技术在重金属检测中的应用进行了综述,并对未来重金属离子传感器的发展进行了展望.     

三聚氰胺修饰电极同位镀铋膜测定镉离子

采用电聚合方法制备三聚氰胺修饰玻碳电极(PM/GC),然后在其表面同位镀铋膜,研究Cd2+在该电极上的溶出伏安行为,并与裸玻碳电极(GC)同位镀铋膜电极上Cd2+的溶出伏安行为进行比较.研究表明,镉在同位镀铋膜的PM/GC电极上可得到灵敏的溶出峰.在优化的实验条件下,镉的氧化峰电流与其在1.0×10～1.O×10-6mol/L浓度范围内呈良好的线性关系,检测下限为5.0×10-8mol/L.由于每次溶出后可方便地将铋膜溶解更新,该方法重现性好.使用铋膜电极替代汞膜电极还有利于保护环境.     

石墨烯/Fe3O4/壳聚糖修饰电极对镉离子的检测研究

镉污染问题严重威胁人类生命健康,因此对镉离子(Cd2+)的快速且高灵敏度检测至关重要.本文通过滴涂法制备了石墨烯/四氧化三铁/壳聚糖/复合膜修饰玻碳电极(GR/Fe3 O4/CS/GCE),采用方波溶出伏安法探讨此修饰电极对Cd2+的溶出伏安响应,优化了电解质、pH值、沉积电位、沉积时间等条件.在最佳条件下,Cd2+的...     

基于阳极溶出伏安法对PLS 算法的重金属离子的同时测定

重金属离子对于环境的污染和人类的危害越来越大，利用阳极溶出伏安法可以提高检测的精度和实现多种离子(Cu、Pb、Cd、Zn)的同时测定。而利用化学统计的方法可以有效的消除溶液中各种离子之间的相互干扰，我们利用偏最小二乘回归方法建立的模型对未知溶液具有很好的预测能力，预测误差不超过15％。另外我们采用超微组合圆盘铂电极，提高了检测的灵敏度，测量精度达ppb。     

离子选择性电极法和电位溶出分析法在食品检测中的作用

本文重点概述离子选择电极和电位溶出分析法在食品检测中的作用。离子选择电极部分主要介绍氟电极、氯电极、硝酸根电极、铅电极、氨电极、糖精电极在食品中的应用情况。电位溶出分析法部分论述八十年代以来几种主要的电位溶出分析技术:常规电位溶出法、微分电位溶出法、流动电位溶出法、计时电位溶出法、流动注射电位溶出法对食品和饮料中有害元素的监测方面所起到的作用。     

铅、镉在铋修饰的厚膜碳浆电极上的阳极溶出伏安法检测

采用阳极溶出伏安法,在厚膜印刷的碳浆电极上同步镀铋测定痕量重金属元素铅和镉.文中研究了碳浆电极的预处理、溶液中铋离子浓度、预富集时间等因素对测量的影响.实验结果表明铅、镉在铋膜修饰的碳浆电极上可得到灵敏的阳极溶出峰,峰高和溶出电位与汞膜电极法相近.使用铋膜电极可避免使用汞电极带来的环境污染,同时采用厚膜印刷的碳浆电极可以大大降低检测成本,实现电极的单次使用.     

基于银染色放大和免疫胶体金的金属免疫分析

提出了一种新的、高灵敏的基于银染色放大和免疫胶体金技术的金属免疫分析方法.免疫反应在聚苯乙烯微孔板中以夹心分析模式进行,通过纳米金对银离子的催化还原在金标抗体上沉积大量的金属银,用酸溶解后,在玻碳电极上用阳极溶出伏安法(ASV)对银离子进行检测,溶出峰电流的大小间接与待分析物人免疫球蛋白G(IgG)的浓度成正比.对阳极溶出分析的测定参数如沉积电位、富集时间和免疫分析的一些条件如抗原-抗体反应时间、金标抗体稀释度等进行了优化.阳极溶出峰电流与IgG浓度在1.66 μg/L～27.25 mg/L范围内呈良好的线性关系,检测下限为1.1 μg/L.     

吸附溶出伏安法在环境检测和药物分析中的应用与进展

吸附溶出伏安法能够测量许多用通常电化学溶出分析难以定量的痕量金属和有机物,并以其灵敏、简单、廉价等特性在环境检测和药物分析中大受欢迎,它是以非电解过程将待测物吸附到工作电极上后,再进行伏安扫描.该文总结了近年来国内外对吸附溶出分析法的研究进展及在环境检测和药物分析中的应用.     

Polymer-grafted QCM chemical sensor and application to heavy metal ions real time detection

A flow type quartz crystal microbalance (QCM) chemical sensor was developed for monitoring heavy metal ions in aqueous solutions (that is suitable for environmental monitoring). The sensor is based upon surface chelation of the metal ions at multifunctional polymer modified gold electrodes on 9 MHz AT-cut quartz resonators, functioning as a QCM. New processes have been developed which enable to obtain surface-modified gold electrodes with high heavy metal ions complexing ability. These polymer grafted QCM sensors can selectively adsorb heavy metal ions, such as copper, lead, chrome and cadmium, from solution over a wide range from 0.01 to 1000 ppm concentration by complexation with functional groups in the polymers. Cations typically present in natural water did not interfere with the detection of heavy metals. X-Ray Reflectivity (XRR) and Total Reflection X-ray Fluorescence (TXRF) were carried out to characterise the unmodified and modified gold surfaces as well as to verify the possibility to selectively bond and remove metal ions.     

A novel electronic tongue combined MLAPS with stripping voltammetry for environmental detection

A kind of integrated electronic tongue device has been developed, which includes a multiple light-addressable potentiometric sensor (MLAPS) and two groups of electrochemical electrodes. MLAPS is based on chalcogenide thin film for the simultaneous detection of Fe(III) and Cr(VI) ions while two groups of electrochemical electrodes, respectively, detect other heavy metals using stripping voltammetry (SV) including anodic and cathode stripping voltammetry. The methods are more convenient for the simultaneous detection of heavy metal in wastewater or seawater and can improve the detection speed and measurement accuracy to many heavy metals. Accordingly a kind of potable electronic tongue instrument to work on-line is also developed.     

A novel method to construct 3D electrodes at the sidewall of microfluidic channel

We report a simple, low-cost and novel method for constructing three-dimensional (3D) microelectrodes in microfluidic system by utilizing low melting point metal alloy. Three-dimensional electrodes have unique properties in application of cell lysis, electro-osmosis, electroporation and dielectrophoresis. The fabrication process involves conventional photolithography and sputtering techniques to fabricate planar electrodes, positioning bismuth (Bi) alloy microspheres at the sidewall of PDMS channel, plasma bonding and low temperature annealing to improve electrical connection between metal microspheres and planar electrodes. Compared to other fabrication methods for 3D electrodes, the presented one does not require rigorous experimental conditions, cumbersome processes and expensive equipments. Numerical analysis on electric field distribution with different electrode configurations was presented to verify the unique field distribution of arc-shaped electrodes. The application of 3D electrode configuration with high-conductive alloy microspheres was confirmed by particle manipulation based on dielectrophoresis. The proposed technique offers alternatives to construct 3D electrodes from 2D electrodes. More importantly, the simplicity of the fabrication process provides easy ways to fabricate electrodes fast with arc-shaped geometry at the sidewall of microchannel.     

Plasma panel‐based radiation detectors

The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels. It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in plasma display panels, it uses nonreactive, intrinsically radiation‐hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low‐mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (<50‐µm RMS) and low cost. In this paper, we report on prototype PPS experimental results in detecting betas, protons, and cosmic muons, and we extrapolate on the PPS potential for applications including the detection of alphas, heavy ions at low‐to‐medium energy, thermal neutrons, and X‐rays.     

Sensing of lead ions using glutathione mediated end to end assembled gold nanorod chains

This communication reports the use of glutathione mediated self assembled chains of gold nanorods as new approach for the detection of Pb²⁺ ions. We were prompted to study the influence of metal ions by considering the role of glutathione as detoxification agent in the body. Additionally the ability of glutathione to complex with metal ions like lead (Pb²⁺) and mercury (Hg²⁺) is well known. We studied the interaction of different metal ions including Pb²⁺ with the end to end assembled chains of gold nanorods. Pb²⁺ was found to disassemble the chains to dimeric structures. High resolution transmission electron microscopy and dynamic light scattering were used to study the ensemble. A proportional reduction in the size of the assembly was observed between concentration ranges of 0.1-0.025 mM of Pb²⁺. Our results indicate that analyte induced disassembly is an attractive approach to the detection of environmentally relevant components such as Pb²⁺.     

中国微米纳米 基于光诱导电化学沉积的金属微电极加工方法

纳米材料具有独特的物理化学性质,在纳米电子器件和生物传感等方面显示了巨大的应用潜力.基于二维纳米材料的器件,需要利用金属电极来构建传感器或者场效应晶体管结构.目前,已有一些方法来制备金属电极,如光刻、聚焦离子束及纳米压印等方法,但是这些方法通常需要昂贵的设备,并且操作非常复杂.提出采用基于光诱导的金属纳米电极沉积方法,通过对多个实验参数(包括输入交流电信号的频率、幅值、溶液浓度以及氢化非晶硅层厚度)的分析,得到了优化的金属电极沉积条件.在此基础上,利用光学显微镜、原子力显微镜和扫描电子显微镜对制备的金属电极进行了表征.     

液态电极发射光谱技术在金属离子检测中应用的研究

研究了采用液态电极等离子体光谱技术来实现金属离子检测的新方法。所建立的测试系统由如下部分组成:被测溶液构成的液态电极、固态对电极、高压发生装置和便携式光谱仪等。液态电极的优点是可以在常温常压下产生放电,并且也不需要复杂的液态样品进样系统,在现场检测等方面具有较大的应用前景。文中研究了放电的各种参数,如放电电压、放电电流、溶液pH值等对元素的光谱发射效率的影响。采用该测试系统,对Na 的检测限为0.1mg/L,而对Li ,K ,Mg2 ,Ca2 等离子的检测限为1mg/L。     

A bio-inspired multi degree of freedom actuator based on a novel cylindrical ionic polymer–metal composite material

In this work, we explore a promising electroactive polymer (EAP), called ionic polymer–metal composite (IPMC) as a material to use as a multi degree of freedom actuator. Configuration of our interest is a cylindrical IPMC with 2-DOF electromechanical actuation capability. The desired functionality was achieved by fabricating unique inter-digitated electrodes. First, a 3D finite element (FE) model was introduced as a design tool to validate if the concept of cylindrical actuators would work. The FE model is based upon the physical transport processes—field induced migration and diffusion of ions. Second, based upon the FE modeling we fabricated a prototype exhibiting desired electromechanical output. The prototype of cylindrical IPMC has a diameter of 1 mm and a 20 mm length. We have successfully demonstrated that the 2-DOF bending of the fabricated cylindrical IPMCs is feasible. Furthermore, the experimental results have given new insight into the physics that is behind the actuation phenomenon of IPMC.