鱼鳔膜为基质的生物传感器测定葡萄糖的研究

以鱼鳔膜为基质同定葡萄糖氧化酶,偶联氧电极,构建了葡萄糖生物传感器,通过测定溶解氧浓度的变化定量测定葡萄糖.考察了酶浓度、pH值、缓冲液浓度对传感器的影响,优化了实验条件:即酶浓度为1 mg,pH 7.0,缓冲液浓度为100 mmol/L.此传感器具有较宽的线性范围(0.016～1.2 mmol/L),较短的响应时间(...     

葡萄糖氧化酶共价交联于蛋膜上的葡萄糖传感器

以牛血清白蛋白－戊二醛为交联剂，将葡萄糖氧化酶固定地鸡蛋膜上，氧电极作电化学敏感元件，制成葡萄糖氧化酶电极。传感器的响应范围为４．０×１０＾－６－２．４×１０＾－３ｍｏｌ／Ｌ；检测限为１．２１０＾－６ｍｏｌ／Ｌ。该传感器具有线性范围宽，灵敏度高，使用寿命长等优点。     

基于微带阵列电极的微型葡萄糖传感器研究

用微电子薄膜技术制作了微带阵列电极（ＭＡＥ）,考察了该电极在铁氰化钾,过氧化氢溶液中的电化学行为。在微带阵列电极表面,修饰一层全氟代磺酸酯膜作为基底电极,并把电子介体二茂铁及葡萄糖氧化酶固定在基底电极上制备了微型葡萄糖传感器,探讨了微酶电极对葡萄糖氧化过程的催化作用。该微酶电极响应时间小于１０ｓ,检测线性上限为８ｍｍｏｌ／Ｌ。     

壳聚糖固定化葡萄糖氧化酶生物传感器测定葡萄糖的含量

应用壳聚糖将葡萄糖氧化酶固定于鸡蛋膜上,结合氧电极制得葡萄糖传感器.实验表明,壳聚糖比戊二醛能更好地固定葡萄糖氧化酶,最佳条件为壳聚糖浓度0.3%、固定化酶量0.8 mg、 pH 7.0、缓冲溶液浓度300 mmol/L和温度25 ℃.本葡萄糖传感器的线性范围为0.016～1.10 mmol/L;检出限为8.0 μmol/L(S/N=3), 响应时间<60 s,有很好的稳定性,寿命>3个月.同一个传感器重复使用以及同方法制作的不同传感器之间都有很好的重现性,RSD分别为2.5%(n=10)和4.7%(n=4).实际样品中可能存在的烟酰胺、 VB6、 VB12、 VE、Ca2+、 Mg2+、 K+和Zn2+等对葡萄糖的测定不产生干扰.本传感器已成功地应用于市售饮料中葡萄糖含量的测定.     

电化学葡萄糖传感器

作为电化学生物传感器中最重要的研究内容之一,葡萄糖生物传感器在数十年的发展中取得了巨大进展。本文综述了近年来利用纳米技术设计的新型电化学葡萄糖传感器的主要研究进展,并从纳米材料维度分类进行了讨论。其中,零维纳米材料主要讨论了包括金纳米颗粒、银纳米颗粒以及铜、铂等金属纳米颗粒材料; 一维纳米材料主要讨论了通过模板法制备的金属或金属氧化物纳米线以及单臂或者多壁纳米管材料; 二维纳米材料主要总结了以碳为基础的石墨烯材料和一些片状的金属材料。纳米材料对电化学葡萄糖传感器的影响主要集中在生物相容性、增强检测灵敏度、酶的固定等方面。此外,本文也对电化学葡萄糖传感器的今后发展做了展望。     

再生丝素和聚乙烯醇混合膜的结构、性能及其葡萄糖传感器的应用

用扫描电镜分析了再生丝素(RSF)和聚乙烯醇(PVA)混合膜的形貌结构,并测定了其吸水性和机械强度,用RSF和PVA的混合材料把葡萄糖氧化酶固定在玻碳电极表面,制成电流型葡萄糖传感器,以1,4-苯醌为电子传递体,酶电极对葡萄糖有灵敏的响应,峰电流的增加与葡萄糖的浓度在10^-5～10^-2mol/L范围内有良好的线性关系。用此方法制成的葡萄糖传感器物理性能好,其有效寿命长达2个月以上。该酶电极对葡萄糖的响应时间小于20s.     

无酶葡萄糖传感器

葡萄糖传感器在几十年的发展中取得了重大进展,经历了三代基于酶葡萄糖传感器之后,现已进入第四代无酶葡萄糖传感器的发展阶段.本文从基于酶和无酶两类介绍了不同葡萄糖传感器的测试原理,综述了近年来纳米材料在无酶电化学葡萄糖传感器方面应用的主要研究进展,对不同类别纳米材料的制备方法以及所构建传感器的灵敏度、选择性、检测范围和稳定性等进行了评述,分析了制约无酶葡萄糖传感器商业化应用的主要原因.其中,贵金属纳米材料主要讨论了铂、金和钯;过渡金属纳米材料主要讨论了镍、铜以及其氧化物;双金属纳米材料主要讨论了合金和复合物;碳纳米材料主要讨论了单壁(多壁)碳纳米管和石墨烯.此外,本文也对无酶葡萄糖传感器的发展方向和趋势进行了展望.     

葡萄糖氧化酶反应体系的动力学性质及在葡萄糖分析中的应用

本文运用紫外－可见光谱仪研究了葡萄糖氧化酶偶联辣根过氧化物酶－邻联茴香胺染料体系的催化动力学性质，通过控制酶和染料的含量，确定了反应呈假一级反应的葡萄糖浓度范围，在此反应体系中，葡萄糖浓度可以通过测定染料吸光度而获得，干扰小，回收率达９７％～１０３％。     

基于聚硫堇和纳米银固定酶的葡萄糖生物传感器

用循环伏安法将电子媒介体硫堇电聚合在玻碳电极表面上,使其表面形成均匀的带负电的聚硫堇膜,通过静电吸附作用吸附表面带正电荷的纳米银溶胶,接着通过静电吸附带负电的葡萄糖氧化酶,最后用聚硫堇包埋电极,从而制得性能优良的葡萄糖氧化酶(GOD)生物传感器。实验发现传感器氧化峰电流与葡萄糖的浓度在1.0×10-8~5.0×10-6mol/L(r=0.9963)范围内呈良好线性关系,检出限为5.0×10-9mol/L(S/N=3)。     

基于普鲁士蓝(PB)膜修饰铂电极的葡萄糖传感器的研究

在制备PB膜修饰铂盘电极的基础上,利用修饰电极对过氧化氢的电催化还原特性,得到了性能优良的葡萄糖传感器。作者系统地考察了有关修饰膜制备和测试实验条件对传感器性能的影响,结果表明传感器的最佳工作电位是0．05V,测试溶液的最适PH值为6．5,在选定的工作条件下,传感器的检测灵敏度为80nA/mmol.L^-1,线性范围为0．1－5mmol.L^-1,响应时间为1．5min,寿命在1个月以上,表观米氏常数为21mmol.L^-1。本方法制得的传感器能有效消除抗坏血酸,尿酸的干扰,有望用于血液中葡萄糖的直接测定。     

An Amperometric Glucose Sensor Based on Isoporous Crystalline Protein Membranes as Immobilization Matrix

Abstract

S-layer ultrafiltration membranes (SUMs) with an active filtration layer composed of coherent two-dimensional, isoporous protein crystals (S-layers) have been used as matrix for immobilizing monolayers of enzymes. Since S-layers are formed by periodic repetition of identical protein subunits, functional groups are present on the crystalline array in an identical position and orientation. As a consequence monolayers of enzymes can bind in a geometrically well defined way. For the covalent immobilization of enzymes carboxyl groups from the S-layer protein were activated with carbodiimide and allowed to react with amino groups of the enzyme. SUMs were employed as a new type of immobilization matrix for the developement of an amperometric glucose sensor using glucose oxidase (GOD) as the biologically active component. Glucose oxidase covalently bound to the surface of the S-layer protein retained approximately 40% of its activity. The enzyme loaded SUMs were covered with a layer of gold or platinum to function as working electrodes. These sensors yielded high signals (150nA/mm²/mmol glucose), fast response times (10–30s) and a linearity range up to 12 mM glucose. The stability under working conditions was more than 48 hours. There was no loss in activity after a storage period of 6 month.     

Glucose Biosensor Based on Oxygen Electrode Part IV: In Vivo Evaluation of the Rechargeable Glucose Sensor

Abstract

A glucose monitoring system consisting of a pair of amperometric sensors: a glucose biosensor based on oxygen electrode and an oxygen sensor, two miniature potentiostats, an instrumentation amplifier and a data logger has been developed. The glucose sensor has linear response to the glucose concentration in vitro at 37°C up to 26 mM (480 mg/dL) in the phosphate buffer solution (pH 7.4), and linear range up to 21 mM (380 mg/dL) in undiluted bovine plasma. The system was evaluated in vivo with the sensors subcutaneously implanted in healthy mongrel dogs. During the implantation the system output was continuously recorded. The results of short-term subcutaneous implantation of the integrated system demonstrated good agreement between the glucose concentration measured by the biosensor and that obtained using standard glucose determination methods. The delay-time between the tissue glucose level (measured by the biosensor) and the blood glucose level (obtained by standard methodology) was 3 to 10 minutes. During the chronic implantation the biosensor was refilled in vivo. Rejuvenation of the sensor response after refilling was observed demonstrating the potential of such sensors for long-term implantation.     

碳纳米管负载铂-二氧化钌纳米颗粒用于葡萄糖传感器的研究

建立了多壁碳纳米管(MWNTs)负载铂二二氧化钌纳米颗粒的液相化学还原法.以Nafion为固定剂,将Pt-RuO2/MWNTs复合材料修饰于玻碳电极的表面,制备了一种无酶型葡萄糖传感器.实验表明:复合材料修饰的电极对葡萄糖响应电流明显,并且受抗坏血酸(AA)、多巴胺(DA)和尿酸(UA)的干扰小.本实验采用安培法测定葡萄糖,线性范围为2 0×10 3～1.0×10-2 mol/L(R～0.9965);灵敏度为119.26 μA cm-2(mmol/L)-1;检出限为1.25×10 -5 mol/L(信噪比为3);响应时间为4.8 s.PtRuO2/MWNTs修饰电极可作为性能良好的无酶型葡萄糖传感器.     

Non-enzymatic Glucose Sensor Based on Porous Foam Au/MXene Nanocomposites

A novel electrochemical non-enzymatic glucose sensor based on three-dimensional Au/MXene nanocomposites was developed. MXenes were prepared using the mild etched method, and the porous foam of Au nanoparticles was combined with the MXene by means of in situ synthesis. By controlling the mass of MXene in the synthesis process, porous foam with Au nanoparticles was obtained. The three-dimensional foam structure of nanoparticles was confirmed by scanning electron microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy were used to study the electrochemical performance of the Au/MXene nanocomposites. The Au/MXene nanocomposites acted as a fast redox probe for non-enzymatic glucose oxidation and showed good performance, including a high sensitivity of 22.45 μA\begin{document}$\cdot$\end{document}(mmol/L)\begin{document}$^{-1}$\end{document}\begin{document}$\cdot$\end{document}cm\begin{document}$^{-1}$\end{document} and a wide linear range of 1-12 mmol/L. Studies have shown that MXene as a catalyst-supported material is beneficial to enhance the conductivity of electrons and increase the loading rate of the catalyst materials. The foam structure with Au nanoparticles can provide a larger surface area, increase the contact area with the molecule in the catalytic reaction, and enhance the electrochemical reaction signal. In summary, this study shows that Au/MXene nanoparticles have the potential to be used in non-enzymatic glucose sensors.     

Diffusion Sensor of Mechanical Signals: Frequency Response at High Frequencies

The frequency response of a diffusion transducer with gauze electrodes, studied theoretically at high frequencies, is proportional to ^-3/2 starting with = D/R ² at < /R ² and to ^-1 at > /R ². Here, = 2f, f is the signal frequency, the electrolyte viscosity, D a diffusion coefficient, and R the radius of the gauze filaments. The calculation is compared with experiment.     

咪唑啉缓蚀剂膜抑制腐蚀介质扩散行为的MD研究

采用分子动力学模拟的方法,对5种1-(2-氨乙基)-2-烷基-咪唑啉缓蚀剂[(NH2)C2H4-C3H4N2-CH2(CH2)nCH3,n=5,7,9,11,13]抑制CO2腐蚀的缓蚀机理进行了研究.计算了4种腐蚀介质粒子(H2O,H3O+,Cl-和HCO-3)在不同缓蚀剂膜中的扩散系数,并从自由体积分数、腐蚀介质粒子与缓蚀剂膜的相互作用、膜的自扩散性能等方面对缓蚀剂膜抑制腐蚀介质粒子扩散行为的微观机理进行了分析.扩散系数的计算结果表明:缓蚀剂膜能有效抑制腐蚀介质的迁移,削弱其腐蚀能力;与中性H2O分子对比,缓蚀剂膜对H3O+,Cl-和HCO-3带电离子的扩散具有更强的抑制效果;随烷基链长的增加,5种缓蚀剂膜对腐蚀粒子扩散的抑制能力呈增强趋势.综合分子动力学计算结果,5种缓蚀剂缓蚀性能随着烷基链长的增加逐渐增强,理论评价结论与实验结论相吻合.     

Glucose Sensor Based On an Amorphous Silicon Isfet

Abstract

An amorphous silicon ion sensitive field effect transistor (a-ISFET) was first applied to glucose sensors. When glucose oxidase was immobilized on the membrane, the sensor gave a linear relationship between the initial rate of the gate output voltage change and the logarithmic value of glucose concentration between 0.1 and 1 mg/ml at pH 7.0, 37°C. Determination of glucose was possible within 1 min. the system can be used for three weeks with only slight loss of enzymatic activity.     

缓蚀剂膜抑制腐蚀介质扩散行为的分子动力学模拟

采用分子动力学模拟方法研究了4种腐蚀介质粒子(H₂O, H₃O⁺, HS^-和Cl^-)在6种不同烷基链长的1-(2-羟乙基)-2-烷基-咪唑啉缓蚀剂膜中的扩散行为. 计算了腐蚀介质粒子在不同缓蚀剂膜中的扩散系数、膜的自由体积分数、粒子与膜的相互作用能等, 并对缓蚀剂膜抑制腐蚀介质粒子扩散行为的微观机理进行了分析. 计算结果表明, 6种缓蚀剂膜均可有效阻碍腐蚀介质粒子向金属表面的扩散, 从而达到抑制或延缓腐蚀的目的; 随烷基链长的增加, 缓蚀剂膜对腐蚀介质粒子扩散行为的抑制能力逐渐增强; 同种缓蚀剂膜对正负离子H₃O⁺, HS^-和Cl^-比对中性的H₂O分子具有更强的扩散抑制能力.     

Dynamics Studies on Molecular Diffusion in Zeolites

1 INTRODUCTION Zeolites have attracted much attention in both scientific and industrial areas for their special characteristics and multiple uses. Zeolites are composed of TO4 (T = Si, Al, Ga, P, etc.) tetrahedra which are connected with each other by sharing oxygen atoms to produce a complex and repetitive three-dimensional atom network with regular molecular dimension cavities joined by channels. Shape selectivity is the most important property of zeolites. Combined with the possib…