Nafion—MV修饰电极丙酮酸氧化酶生物传感器测定GPT的研究

用Nafion-甲基紫精修饰电极为基底,以牛血清白蛋白戊二醛为交联剂,将丙铜酸氧化酶固定在电极上,制成丙酮酸氧化酶生物传感器.用这种生物传感器测定人体血清中谷丙转氨酶(GPT)的活性,共存的尿酸、抗坏血酸等电活性物质不干扰测定.测定GPT的活性范围为0～110U/L,响应时间为50s.该传感器具有灵敏度高、抗干扰能力强和响应快等特点.     

多糖激活的酪氨酸酶生物电极测定酚类的研究

研制了以麦芽糊精作为酪氨酸酶的激活剂 ,采用Nafion117膜抗阴离子干扰 ,聚乙烯亚胺 (PEI)作包埋剂以抗阳离子干扰的酪氨酸酶碳糊电极。工作电位为 - 10 0mV [vs.Hg/Hg2 Cl2(s) ],pH为 5 .4 0 ,测量时间为 1.0min。在此测量条件下 ,电极对苯酚的检出限为 5 .0× 10 - 8mol·L- 1,线性范围为 2 .0× 10 - 7～ 5 .0× 10 - 5mol·L- 1,RSD为 1.2 %。用所研制电极测定炼油废水中酚的含量 ,加标回收率为 10 0 .7%。     

生物传感器的研究.V.尿素—石竹花组结电极的研究

尿素—石竹花组织电极是一种植物组织传感器。文中叙述了一种完整石竹花瓣的固定新方法,改善了此类生物传感器的性能:线性范围7.6×10~(-(?))～1.0×10~(-3)mol·L~(-1),斜率47mv·decade~(-1),检测上下限分别为3.2×10~(-3)mol·L~(-1)和4.6×10~(-6)mol·L~(-1),响应时间15～20min,寿命14天.该电极已初步用于实际样品的测定,结果与凯氏法吻合。对尿素含量为3.0×10~(-4)mol·L~(-1)的样品,本法分析结果偏差≤0.2×10~(-4)mol·L~(-1),平均回收率为101.5%(M=3,n=3),表明该传感器具有一定的实用价值。     

丝氨酸织组膜电极的研究

利用猪肝组织膜配合氨气敏电极,研制了丝氨酸生物催化传感电极。丝氨酸浓度的测定范围为5.1×10~(-5)～3.2×10~(-3)mol/L,检出限为3.1×10~(-5)mol/L。研究和讨论了电极的最佳工作条件,并测定了实验条件下酶催化反应的米氏常数Km。该电极用于合成样品分析,效果满意。     

Nafion-甲基紫精修饰电极抗坏血酸氧化酶生物传感器的研究

本文用Nafion-甲基紫精修饰电极为基底,以牛血清白蛋白和戊二醛为交联剂,将抗坏血酸氧化酶固定在电极上,制成修饰电极抗坏血酸氧化酶生物传感器。用这种生物传感器测定人体血清中抗坏血酸,线性范围在7.5×10~(-4)～7.5×10~(-7)mol/L之间,响应时间为5s,检测下限为2.5×10~(-7)mol/L。该传感器具有选择性好、灵敏度高和响应时间短等特点。     

钴卟啉修饰电极为基底的葡萄糖酶电极

生物电化学传感器的开发和应用是目前电分析化学研究中的一个重要方向,其中最引人注目的是电流式生物电化学传感器的研究。传统的电流式生物电化学传感器的基础电极采用的是能检测氧气和过氧化氢的贵金属电极。本文采用四苯基钴卟啉化学修饰电极代替     

基于碳纳米管的化学修饰电极及电化学生物传感器的研究进展

综述了碳纳米管的结构、合成、纯化、功能化、分散及基于碳纳米管的化学修饰电极和电化学生物传感器的研究进展。     

Glucose Dehydrogenase Based Bioelectrode Utilizing a Synergistic Scheme of Substrate Conversion

A Bioelectrode utilizing a synergistic scheme of substrate conversion was built using glucose dehydrogenase from Acinetobacter calcoaceticus immobilized on the surface of a graphite electrode. At saturated glucose concentration the bioelectrode responded to the low reactive substrate hexacyanoferrate(III) with a sensitivity of 0.0035 µA/µM cm². The response of the bioelectrode increased up to the 3.4×10⁴ fold in the presence of high reactive organic electron acceptors (mediators). The increase of the response depended on the concentration of the mediators and their chemical nature. The sensitivity of the bioelectrode to mediators reached 7.3–77 µA/µM cm². The comparison of the bioelectrode sensitivity with kinetic parameters of enzyme action in homogeneous solution revealed good correlation between the sensitivity of the bioelectrode and the predicted value from the kinetic scheme of the reactivity of mediators. This confirms a synergistic scheme of bioelectrode action.     

青椒籽浆-碳糊生物电极的研制及应用

本文研制了青椒籽浆-碳糊生物电极,并探讨了电极的性能及实用性,实验表明,该电极可用于伏安法快速检测L-抗坏血酸,线性范围为1.15×10~(-5)～1.24×10~(-4)mol/L,检测下限可达到9.87×10~(-6)mol/L,电极具有良好的重现性和选择性,响应时间短,使用寿命为12d。     

SiO2 coated Fe3O4 magnetic nanoparticle dispersed multiwalled carbon nanotubes based amperometric glucose biosensor

A new type of amperometric glucose biosensor based on silicon dioxide coated magnetic nanoparticle decorated multiwalled carbon nanotubes (Fe₃O₄@SiO₂/MWNTs) on a glassy carbon electrode (GCE) has been developed. MWNTs have been synthesized by catalytic chemical vapour decomposition (CCVD) of acetylene over rare earth (RE) based AB₃ alloy hydride catalyst. The as-grown MWNTs have been purified and further functionlized. Functionalized MWNTs have been decorated with magnetic Fe₃O₄ nanoparticles which have been uniformly coated with biocompatible SiO₂ using a simple chemical reduction method. The characterization of magnetic nanoparticle modified MWNTs have been done by X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), energy dispersive X-ray analysis (EDX) and UV-vis spectroscopy. Amperometric biosensor has been fabricated by the deposition of glucose oxidase (GOD) over Nafion-solubilized Fe₃O₄@SiO₂/MWNTs electrode. The resultant bioelectrode retains its biocatalytic activity and offers fast and sensitive glucose quantification. The performance of the biosensor has been studied using cyclic voltammetry and amperometry and the results have been discussed. The fabricated glucose biosensor exhibits a linear response from 1 μM to 30 mM with an excellent detection limit of 800 nM indicating the potential applications in food industries.     

生物电极的原位FTIR反射光谱研究

利用原位FTIR反射光谱对介体型酶电极、酶免疫电极进行了研究 .通过不同电极电位下的电位差谱和同一电位不同状态下的单光束光谱之差 ,确定并解析了葡萄糖氧化酶 (GOD)和葡萄糖的特征谱峰 ,同时 ,还初步研究了酶免疫电极的红外吸收特征     

Electrochemical Peroxidase‐Catalase Clark‐Type Biosensor: Computed and Experimental Response

A bioelectrode containing immobilized catalase and peroxidase was built using a Clark‐type oxygen electrode. The bioelectrode responded to hydrogen peroxide (H₂O₂) as well as to acetaminophen (Ac). The sensitivity of the bioelectrode for H₂O₂ was 0.35 mM O₂/mM H₂O₂ and for Ac it was 0.23–1.05 µM O₂/µM Ac at pH 6.6 and 25 °C. The limit of detection of Ac varied from 12 to 44 µM. The half‐time of the bioelectrode response to hydrogen peroxide was 36 s. The modeling of the bioelectrode action was performed digitally at transition and steady‐state conditions using finite difference technique. The calculated half‐time of the bioelectrode response to hydrogen peroxide was 53 % larger and the steady‐state response 11 % less than experimentally determined. The response to Ac was 2–3 times smaller in comparison to the experimental values. The calculated response change correlated with the experimentally determined when the catalase and peroxidase concentrations in the biocatalytical membrane changed 3–4 orders of magnitude. The simulations of the bioelectrode response revealed that the bioelectrode acts in diffusion limiting conditions at almost all enzymes concentrations. The model appears to be promising for optimization of the bioelectrode response.     

辣根过氧化酶溶胶-凝胶膜修饰电极与过氧化氢的安培检测

1　引　　言溶胶 凝胶法一般是以金属盐或半金属盐做前驱体 (硅酸甲酯ＴＭＯＳ、硅酸乙酯ＴＥＯＳ、钛酸丁酯等 )在水、互溶剂及催化剂的存在下发生水解和缩聚反应 ,形成ＳｉＯ2 三维网络结构。在成胶的过程中 ,若引入掺杂组分 ,可将其包埋于三维网络结构中。以二氧化硅作为传感器的工作平台 ,其优点在于它具有良好的坚固性、化学惰性、高的光稳定性和透过性 ,同时溶胶凝胶过程还具有纯度高 ,均匀性强 ,反应条件易于控制并易于实现多种产品构型等优点 ,可为各种类型生物传感器的开发和制作提供更多的机会和条件。辣根过氧化酶 (ＨＲＰ)是一…     

电化学式生物传感器的近期发展动向

电化学式生物传感器是生物传感器的很重要组成部分。新材料用于生物传感器是其新发展的重要研究方向,它包括PVC膜的替代材料,离子交换聚合物膜,有机导电聚合物和氧化还原聚合物等。各学科的相互渗透,使生物传感器出现新颖的设想和概念,包括氧化还原酶的电子导通,超薄组成膜和化学敏感微电化学装置及离子通道传感器与膦酯膜电极。电子鼻和组电极以及生物传感器的微型化都是生物传感器的新发展动向。     

Review of recent advances in analytical techniques for the determination of neurotransmitters

Methods and advances for monitoring neurotransmitters in vivo or for tissue analysis of neurotransmitters over the last five years are reviewed. The review is organized primarily by neurotransmitter type. Transmitter and related compounds may be monitored by either in vivo sampling coupled to analytical methods or implanted sensors. Sampling is primarily performed using microdialysis, but low-flow push-pull perfusion may offer advantages of spatial resolution while minimizing the tissue disruption associated with higher flow rates. Analytical techniques coupled to these sampling methods include liquid chromatography, capillary electrophoresis, enzyme assays, sensors, and mass spectrometry. Methods for the detection of amino acid, monoamine, neuropeptide, acetylcholine, nucleoside, and soluble gas neurotransmitters have been developed and improved upon. Advances in the speed and sensitivity of these methods have enabled improvements in temporal resolution and increased the number of compounds detectable. Similar advances have enabled improved detection at tissue samples, with a substantial emphasis on single cell and other small samples. Sensors provide excellent temporal and spatial resolution for in vivo monitoring. Advances in application to catecholamines, indoleamines, and amino acids have been prominent. Improvements in stability, sensitivity, and selectivity of the sensors have been of paramount interest.     

Ionic Liquid‐Hemoglobin‐Carbon Paste Composite Bioelectrode and Its Electrocatalytic Activity

A new carbon ionic liquid paste bioelectrode was fabricated by mixing hemoglobin (Hb) with graphite powder, ionic liquid 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF₄) and liquid paraffin homogeneously. Nafion film was cast on the electrode surface to improve the stability of bioelectrode. Direct electrochemistry of Hb in the bioelectrode was carefully investigated. Cyclic voltammetric results indicated that a pair of well‐defined and quasi‐reversible electrochemical responses appeared in pH 7.0 phosphate buffer solution (PBS), indicating that direct electron transfer of Hb was realized in the modified electrode. The formal potential (E^0′) was calculated as ?0.316 V (vs. SCE), which was the typical characteristic of the electrochemical reaction of heme Fe(III)/Fe(II) redox couple. Based on the cyclic voltammetric results the electrochemical parameters of the electrode reaction were calculated. This bioelectrode showed high electrocatalytic activity towards the reduction of trichloroacetic acid (TCA) with good stability and reproducibility.     

Enhancement of bioelectrochemical dioxygen reduction with oxygen-enriching materials

Bioelectrochemical dioxygen reduction reaction (ORR) catalyzed by multi-copper oxidases (MCOs) is a process of paramount importance occurring at the cathode of enzymatic biofuel cells (EBFCs), which is an energy harvester that holds promise of self-sustained implantable and wearable medical devices. The MCO biocathode is, however, frequently the limiting factor of a working EBFC. Besides the operational stability issue, enzymatic biocathodes are largely constrained by the relatively low solubility of dioxygen in aqueous solution. As an emerging topic, we here review the introduction of dioxygen-enriching materials to the cathodic bioelectrode for overcoming the dioxygen supply limitation, leading to improved ORR performance.