人体唾液葡萄糖生物传感器

通过戊二醛交联法将葡萄糖氧化酶(GOD)固定在二茂铁(Fc)修饰的薄膜金电极上,制备了一种可用于检测人体唾液中葡萄糖含量的生物传感器。研究了不同扫描速度下二茂铁的电化学行为,以及工作电压、戊二醛浓度和酶固定量对传感器响应特性的影响。结果表明,利用戊二醛交联法制备的传感器检出限低、检测范围宽。在0~2 200μmol/L的葡萄糖标准浓度范围内,传感器灵敏度为21.45nA.μmol-1.cm-2(相关系数r=0.991 2),检出限为1μmol/L,响应时间5s。该结果可实现对唾液葡萄糖的检测,进而有望实现对血糖的检测。     

基于分子印迹聚合膜的胆固醇丝网印刷生物传感芯片

该文基于自组装技术在丝网印刷金电极表面制备分子印迹膜,研制胆固醇电化学仿生生物传感芯片。利用扫描电镜(SEM)对平面裸金电极、厚膜裸金电极及其修饰电极进行了形貌的分析比较,采用循环伏安分析法对电极修饰过程的电化学特性进行表征,采用计时电流法对胆固醇生物传感芯片的浓度响应特性进行检测。结果表明, 基于丝网印刷工艺的厚膜电极不仅能满足自组装分子印迹仿生膜的修饰,而且电极表面具有明显的纳米放大效应。传感器对0~700 nM不同浓度胆固醇进行检测,线性范围50 nM~700 nM,灵敏度达到-4.94 A/[lg(nM)],线性相关系数为0.994。该胆固醇传感芯片具有较高的准确性,检测准确度达到了99.56%。     

纳米金表面修饰提高压电免疫传感器性能研究

在石英晶体微天平的金电极上通过1,6-己二硫醇交联组装纳米金颗粒修饰传感器表面,同时结合蛋白A与抗体的Fc段特异性结合的特性定向固定人IgG构建压电免疫传感器,并用于羊抗人IgG的检测.实验结果表明,与未经修饰相比,纳米金颗粒组装修饰金电极后能明显提高压电免疫传感器的检测灵敏度、重现性和再生能力等重要性能指标,修饰后的传感器也具有非常好的在线再生性能.     

金属支架对BLM的K 离子敏感特性的影响

BLM(双层类脂膜)的金属支撑构成了一种电化学传感器.这种传感器的化学反应和电现象之间的转化,是通过金属对BLM的支撑来实现的,不同于经典的电化学换能器.用缬氨霉素修饰的BLM作为敏感膜,制成金属-BLM和经典电化学K 离子电极.通过两种电极对K 离子检测的对比实验,以及不同直径和新鲜面不同给出方法的金属-BLM电极的对比实验,探讨了BLM的金属支撑对BLM的K 离子敏感特性的影响.从实验数据看,BLM的金属支撑在性能上优于经典电化学传感器,但支撑介质的新鲜面对BLM的K 离子敏感特性有影响.     

金属支架对BLM的K+离子敏感特性的影响

BLM(双层类脂膜)的金属支撑构成了一种电化学传感器.这种传感器的化学反应和电现象之间的转化,是通过金属对BLM的支撑来实现的,不同于经典的电化学换能器.用缬氨霉素修饰的BLM作为敏感膜,制成金属-BLM和经典电化学K+离子电极.通过两种电极对K+离子检测的对比实验,以及不同直径和新鲜面不同给出方法的金属-BLM电极的对比实验,探讨了BLM的金属支撑对BLM的K+离子敏感特性的影响.从实验数据看,BLM的金属支撑在性能上优于经典电化学传感器,但支撑介质的新鲜面对BLM的K+离子敏感特性有影响.     

基于铂黑的微针电极阵列表面修饰方法

由于微针电极阵列尖端直径小,空间分辨率高,可以记录单个神经元的放电活动,已成为神经信号记录的首选。但商用微针电极阵列的阻抗较高,降低电极阻抗有利于提高信噪比,改善记录信号质量。采用超声电镀铂黑的方法对微针电极表面进行修饰。测试结果表明铂黑修饰后的微针电极电化学性能优异,1 kHz处阻抗约为2.5 kΩ,相比裸金电极降低了两个数量级,电荷存储量增加到2.988×10-6 C。此外,机械超声测试和循环伏安扫描测试证明了电极具有良好的机械和电化学稳定性。这使铂黑修饰的微针电极阵列有望在体内植入研究中实现电极所需的高灵敏度及高空间分辨率。     

电源技术 电源基础

0625852硫化氢间接电解制氢电极材料性能研究〔刊,中〕/邢定峰//中国石油大学学报(自然科学版).—2006,30(3).—126-130,134(E)0625853二茂铁甲酸/L-半胱氨酸修饰金电极的制备及对抗坏血酸的电催化测定〔刊,中〕/谢友斌//安徽师范大学学报(自然科学版).—2006,29(3).—258-261(E)0625854细胞色素C/L-半胱氨酸修饰电极的电化学行为研究〔刊,中〕/刘云春//安徽师范大学学报(自然科学版).—2006,29(3).—255-257(E)采用自组装饰法将细胞色素C修饰到以L-半胱氨酸为连接剂的金电极上,并运用循环伏安法(CV)、电化学阻抗法(EIS)等方法研究了…     

量子点-DNA电化学发光传感器的制备与表征

为实现对特定基因序列的快速、灵敏检测,该文制备了一种基于碲化镉量子点的DNA电化学发光传感器并对测试条件进行了优化。电化学发光传感器是以金电极作基底,然后依次键合L-半胱氨酸和探针单链DNA。采用循环伏安法和电化学阻抗谱法对传感器的组装过程进行表征。电化学发光试剂碲化镉量子点标记的目标DNA与探针DNA杂交构成电化学发光传感器体系。结果表明,扫描时间6s,扫描电位-3.0~-1.5V,扫描速率0.1V/s时,电化学发光传感器体系的电化学发光效果最佳。     

集成Ti/TiO2敏感电极和液接式Ag/AgCl参比电极的pH微纳传感器

常见的pH传感器大多采用电位法进行检测,基于电位法进行检测的传感器由敏感电极和参比电极组成.在尺寸仅为5 mm×5 mm的传感器芯片上制备了钛电极、银电极和铂电阻丝.采用电化学氧化的方法对钛电极进行阳极氧化制成Ti/TiO2敏感电极.采用电化学氯化的方法对银电极进行阳极氯化,再将饱和KC1溶液(3 mol/L)注入参比...     

金属支架对BLM的K+离子敏感特性的影响

BLM（双层类脂膜）的金属支撑构成了一种电化学传感器。这种传感器的化学反应和电现象之间的转化，是通过金属对BLM的支撑来实现的，不同于经典的电化学换能器。用缬氨霉素修饰的BLM作为敏感膜，制成金属-BLM和经典电化学K^＋离子电极。通过两种电极对K^＋离子检测的对比实验，以及不同直径和新鲜面不同给出方法的金属-BLM电极的对比实验，探讨了BLM的金属支撑对BLM的K^＋离子敏感特性的影响。从实验数据看，BLM的金属支撑在性能上优于经典电化学传感器，但支撑介质的新鲜面对BLM的K^＋离子敏感特性有影响。     

染料敏化太阳能电池TiO2薄膜电极的染料吸附性能研究

采用手工刮涂法制备了染料敏化太阳能电池( DSSC)的TiO2薄膜电极,用解吸的方法和正交试验研究了DSSC电池TiO2薄膜电极的染料吸附性能,并结合统计分析方法对染料吸附试验数据进行了分析处理.研究结果表明TiO2薄膜电极具有最优染料吸附性能的烧结条件为:以2℃/min的速率升温至450℃,保温50 min后随炉冷却...     

Modified PEDOT-PSS Conducting Polymer as S/D Electrodes for Device Performance Enhancement of P3HT TFTs

Poly(3,4-ethylenedioxythiophene)—Polystyrene Sulfonate (PEDOT-PSS) is the most widely used conducting polymer as electrode material in organic (polymer) devices. However, commercially available PEDOT-PSS in our experiment has a relatively low conductivity that reduces the device performance when it is used for electrode material. The purchased PEDOT-PSS has been mixed with polar solvent dimethyl sulfoxide, which increases its conductivity from 0.07 to 30 S/cm. The enhanced conductivity has long-term stability at room temperature and short-term stability at high temperature (100$^circ$C) in air ambient. The modified PEDOT-PSS has been inkjet printed and used as source/drain (S/D) electrodes for poly(3-hexylthiophene) (P3HT) thin-film transistors (TFTs). Unmodified PEDOT-PSS and gold have also been used as S/D electrodes for comparison. The TFTs with modified PEDOT-PSS electrodes show significantly improved performance over the devices with unmodified PEDOT-PSS electrodes and are similar to the devices with gold electrodes. The difference in device performance mainly results from parasitic series resistance. In the devices with unmodified PEDOTT-PSS, high electrode series resistance has several effects on devices, e.g., restricted current growth at high negative gate voltage, reduced on/off current ratio and current output capability.     

Bottom-contact poly(3,3‴-didodecylquaterthiophene) thin-film transistors with reduced contact resistance

A dramatic, ∼20-fold, reduction in the contact resistance of the bottom-contact poly(3,3‴-didodecylquaterthiophene) (PQT-12) thin-film transistors was achieved through a simple treatment of gold (Au) source and drain electrodes. The Au electrode treatment involved simply immersing the Au electrodes into Piranha solution prior to the deposition of the organic semiconductor. This treatment led to significant improvement of device performance. Channel length scaling analysis indicates that the contact resistance is reduced by about one order of magnitude, resulting in enhancement of estimated field-effect mobility by about a factor of five. Transport characteristic analysis suggests that the improved efficiency of charge carrier injection is probably due to increased dopant density of PQT-12 at the electrode/PQT-12 interface.     

Multi-enzyme electrode using hydrogen-ion-sensitive field-effect transistors

The feasibility of a multi-enzyme electrode for simultaneous determination of glucose and urea has been investigated. The multi-enzyme electrode consisted of three hydrogen-ion-sensitive field-effect transistors (pH-ISFET) with a platinum wire as a pseudoreference electrode. The firstpH-ISFET had an immobilized glucose oxidase (GOD) membrane, the second one had an immobilized urease membrane, and the third one had no enzyme membrane. The enzymes were immobilized by a water-soluble photocrosslinkable polymer over the pH-ISFET's, and the enzyme-photocrosslinked polymer membranes thus obtained were further hardened by the reaction of bovine serum albumin (BSA) that has been added to the enzyme-polymer mixture with glutaraldehyde. The multi-enzyme electrode can be used for determining glucose and urea over the concentration range 50-1000 mg/l. The multi-enzyme electrode was shown to be potentially promising, although it requires some improvements for practical applications.     

Electrocatalytic Determination of Glucose in a Ringer''s Solution by Pulse-Voltammetry

Improvement of the electrocatalytic method of glucose determination was achieved by applying the pulse voltammetry technique. This technique, compared. to previously applied cyclic voltammetry, enhances selectivity of a platinum-black working electrode for glucose measurement. A low catalytic load working electrode has been used which is less susceptible to poisoning and has longer term stability. With cyclic voltammetry previously applied, those electrodes were limited by their narrow concentration range for glucose detection. By applying a pulsing technique, these electrodes exhibit linearity up to a glucose concentration 200 mg/dl with correlation coefficients greater than 0.9. The pulse voltammetry diminishes interference by low molecular weight serum components such as serum urea. Concentrations from 20. to 40 mg/di had an interference of 4 percent compared to 40 percent with cyclic voltammetry. Further investigations are carried on to adopt pulse voltammetry for direct measurements of glucose in body fluids.     

Electrode polarization impedance in weak NaCl aqueous solutions

In this paper, we characterize the polarization impedance behavior of several common metals in diluted NaCl solution operated at low current densities. The objective was to provide a useful reference for those wishing to calculate the electrode polarization impedance in diluted NaCl solutions. Serial equivalent resistance (R) and capacitance (C) for silver, aluminum, gold, platinum, and medical stainless-steel were measured as a function of frequency (10(-2)-10(3) Hz) and NaCl concentration (2.4-77.0 mmol/L). The ratio of electrode polarization impedance with respect to the bulk resistance was calculated and plotted against concentration for each metal. Such a ratio shows the effect of the electrode polarization contribution as a function of electrolyte concentration when the bulk resistance of the solution changes. All metals showed a decrease of serial resistance Rp and capacitance Cp as a function of frequency. The medical stainless-steel electrode showed largest impedance values at lower frequencies compared to the other electrodes, and was concentration independent at all frequencies. Aluminum had smallest polarization impedance at low frequencies. Pure gold and platinum behaved similar with the exception that the serial resistance for gold showed a lower value at higher frequencies.     

Thin-Film Multiple Electrode Probes: Possibilities and Limitations

Thin-film multiple electrode probes are produced by means of thin-film techniques. They are successfully employed for potential measurements in brain research. The most advantageous feature of these probes is that the electrodes can be designed and arranged accurately and close together. The geometric size of the electrode areas is usually in the range of between 50 and 10 000 ?m2. The size limitations of these thin-film probes are mainly determined by the electrode-electrolyte interface and insulation layer qualities. Since medical research problems, as well as surgical requests, are stressing these limitations, some estimates of maximum resolution and probe dimensions are presented.     

Inkjet‐Printed Flexible Gold Electrode Arrays for Bioelectronic Interfaces

Bioelectronic interfaces require electrodes that are mechanically flexible and chemically inert. Flexibility allows pristine electrode contact to skin and tissue, and chemical inertness prevents electrodes from reacting with biological fluids and living tissues. Therefore, flexible gold electrodes are ideal for bioimpedance and biopotential measurements such as bioimpedance tomography, electrocardiography (ECG), electroencephalography (EEG), and electromyography (EMG). However, a manufacturing process to fabricate gold electrode arrays on plastic substrates is still elusive. In this work, a fabrication and low‐temperature sintering (≈200 °C) technique is demonstrated to fabricate gold electrodes. At low‐temperature sintering conditions, lines of different widths demonstrate different sintering speeds. Therefore, the sintering condition is targeted toward the widest feature in the design layout. Manufactured electrodes show minimum feature size of 62 μm and conductivity values of 5 × 10 ⁶ S m^?1. Utilizing the versatility of printing and plastic electronic processes, electrode arrays consisting of 31 electrodes with electrode‐to‐electrode spacing ranging from 2 to 7 mm are fabricated and used for impedance mapping of conformal surfaces at 15 kHz. Overall, the fabrication process of an inkjet‐printed gold electrode array that is electrically reproducible, mechanically robust, and promising for bioimpedance and biopotential measurements is demonstrated.     

In vivo inflammatory and wound healing effects of gold electrode voltammetry for MEMS micro-reservoir drug delivery device

The in vivo biocompatibility and biofouling of gold electrodes for a microelectromechanical systems drug delivery device were investigated in a rodent model. The role of the applied voltage and gold electrolysis products in modulating the inflammatory response (biocompatibility), and the temporal adhesion of cellular populations onto macroscopic gold film electrodes (biofouling) were analyzed in reference to two controls, devices to which voltage was not applied (uncorroded) or voltage was applied to inert platinum electrodes (electrical controls). Voltammetry was applied to the gold surfaces once (day 4, 7, 14, 21, 28, 35, 42, or 49), while voltage of identical magnitude was applied to the electrical controls. An inflammatory response characterized by a rapid decrease of leukocyte concentration to control levels was observed 48 h following voltage application with no significant cell concentration difference (p > 0.05) between the corroded devices and electrical controls. The histological evaluation of the direct implant fibrous capsule showed comparable thickness of voltage applied and control specimens. The gold corrosion peak current showed no significant difference (p > 0.05) among peak values at all time points. It was concluded that gold electrode corrosion was biocompatible and its electrochemical performance was not hindered by fibrous capsule formation.