Amperometric Glucose Biosensor Based on Ultrafine Platinum Nanoparticles

Abstract

In the present paper the ultrafine and highly dispersed platinum nanoparticles (average size 3 nm) were used for the construction of a glucose biosensor in a simple method. An excellent response to glucose has been obtained with a high sensitivity (137.7 µA mM^?1 cm^?2) and fast response time (5 s). The biosensor showed a detection limit of 5 µM (at the ratio of signal to noise, S/N=3) and a linear range form 0.2 to 3.2 mM with a correlation coefficient r=0.999. The apparent Michaelis–Menten constant (k _m) and the maximum current were estimated to be 9.36 and 1.507 mA mM^?1 cm^?2, respectively. In addition, effects of pH value, applied potential and the interferents on the amperometric response of the sensor were investigated and discussed.     

Evaluation of Some Redox Mediators in the Design of Reagentless Amperometric Glucose Biosensor

The influence of redox mediators (tetrathiafulvalene (TTF), tetrathiafulvalene‐tetracyanoquinodimethane complex (TTF‐TCNQ), phenazine methosulfate (PMS), 5,6‐diamino‐1,10‐phenonthroline (5,6‐DAP), potassium ferrocyanide (K4[Fe(CN)6]), methylene blue (MB) and toluidine blue (TB)) on the response of amperometric glucose biosensor was investigated in this research. Graphite rod electrode (GRE) modified by adsorbed mediator and glucose oxidase (GOx) cross‐linked with glutaraldehyde was served as working electrode. The highest amperometric signals were observed by using TTF and TTF‐TCNQ as mediators. The impact of amount of immobilized GOx, an optimal pH region for operation, stability and reproducibility of the analytic signal of designed biosensor using these mediators were investigated and discussed.     

Biosensing Membrane Base on Ferulic Acid and Glucose Oxidase for an Amperometric Glucose Biosensor

A biosensing membrane base on ferulic acid and glucose oxidase is synthesized onto a carbon paste electrode by electropolymerization via cyclic voltammetry in aqueous media at neutral pH at a single step. The developed biosensors exhibit a linear response from 0.082 to 34 mM glucose concentration, with a coefficient of determination R² equal to 0.997. The biosensors display a sensitivity of 1.1 μAmM⁻¹ cm⁻², a detection limit of 0.025 mM, and 0.082 mM as glucose quantification limit. The studies reveal stable, repeatable, and reproducible biosensors response. The results indicate that the novel poly-ferulic acid membrane synthesized by electropolymerization is a promising method for glucose oxidase immobilization towards the development of glucose biosensors. The developed glucose biosensors exhibit a broader linear glucose response than other polymer-based glucose biosensors.     

A New Amperometric Glucose Biosensor with Naphthol Green B as Mediator

Naphthol green B was used, for the first time, as a new mediator in an amperometric glucose biosensor. It is a good mediator, promoting electron transfer from glucose oxidase to graphite electrode. The biosensor shows high sensitivity to glucose at low potential with response time of 30 seconds. The linear range is from 1.5 to 18μmol/L glucose with detection limit of 0.5μmol/L glucose.     

高效毛细管电泳安培检测的进展

本文对高效毛细管电泳电化学检测方法中的安培检测进行了评述，安培检测具有灵敏度高，选择的特点，安培检测根据毛细管内径的大小有离柱安培检测和柱端安培检测，近年来脉冲安培分析法、化学修饰电极也已被引入毛细管电泳电化学检测。     

Development of a Novel Silver Nanoparticles-Enhanced Screen-Printed Amperometric Glucose Biosensor

Abstract

A disposable glucose biosensor is developed by immobilizing glucose oxidase into silver nanoparticles-doped silica sol-gel and polyvinyl alcohol hybrid film on a Prussian blue-modified screen-printed electrode. The silver nanoparticles-enhanced biosensor shows a linear amperometric response to glucose from 1.25 × 10^?5 to 2.56 × 10^?3 with a sensitivity of 20.09 mA M^?1 cm^?2, which is almost double that of the biosensors without silver nanoparticles. The immobilized glucose oxidase retained 91% of its original activity after 30 days of storage in phosphate buffer (pH 6.9; 0.1 M) at 4°C. Blood glucose in a rabbit serum sample was successfully measured with the biosensor.     

用高效毛细管电泳安培法检测扑热息痛及其水解物对氨基酚

采用高效毛细管电泳安培法对扑热息痛及其水解物对氨基酚的测定进行了研究。优化选择了工作电极、检测电位、缓冲沉沦浓度等实验参数,并探讨了进样时间与峰电流的关系。结果表明：在优化的实验条件下扑热息痛和对氨基酚在６ｍｉｎ内可以得到较好的分离,检出限分别为０．５ｕｍｏｌ／Ｌ和１．０ｒｍｏｌ／Ｌ。该法适合药物生产过程的质量控制和临床检测。     

高效毛细管电泳碳柱电极安培电化学检测的理论研究

推导了高效毛细管电泳碳柱电极安培电化学检测的检测电流表达式，并以自制毛细管电泳／电化学检测系统对其进行了实验验证。对给定直径的工作电极，检测电流正比于碳柱工作电极插入检测毛细管长度的２／３次方，也正比于液体电渗平均体积流速的１／３次方。实验结果与公式吻合很好，说明了检测电流表达式的正确性。     

肉类中己烯雌酚的高速毛细管电泳安培法测定

采用高速毛细管电泳安培法对人工合成雌激素———己烯雌酚 (DES)的测定进行了研究 ;通过优化选择检测电位、毛细管内径和长度、分离电压、缓冲溶液等实验参数 ,DES在60s内可以得到较好的分离 ,检出限为1.0×10 -8mol/L ,DEC浓度在1.48×10 -4～3.69×10 -5mol/L ,1.25×10 -6～1.85×10 -7mol/L与峰面积分段呈良好的线性关系 ;迁移时间和峰面积的相对标准偏差分别为0.65 %、2.2 % ;将该法用于市售肉类中DES的检测 ,取得了满意的结果     

Amperometric Biosensor Based on Enzymatic Reactor for Choline Determination in Flow Systems

A simple, selective and stable biosensor with the enzymatic reactor based on choline oxidase (ChOx) was developed and applied for the determination of choline (Ch) in flow injection analysis with amperometric detection. The enzyme ChOx was covalently immobilized with glutaraldehyde to mesoporous silica powder (SBA‐15) previously covered by NH₂‐groups. This powder was found as an optimal filling of the reactor. The detection of Ch is based on amperometric monitoring of consumed oxygen during the enzymatic reaction, which is directly proportional to Ch concentration. Two arrangements of an electrolytic cell in FIA, namely wall‐jet cell with working silver solid amalgam electrode covered by mercury film and flow‐through cell with tubular detector of polished silver solid amalgam were compared. The experimental parameters affecting the sensitivity and stability of the biosensor (i. e. pH of the carrier solution, volume of reactor, amount of the immobilized enzyme, the detection potential, flow rate, etc.) were optimized. Under the optimized conditions, the limit of detection was found to be 9.0×10^?6 mol L^?1. The Michaelis‐Menten constant for covalently immobilized ChOx on SBA‐15 was calculated. The proposed amperometric biosensor with the developed ChOx‐based reactor exhibits good repeatability, reproducibility, long‐term stability, and reusability. Its efficiency has been confirmed by the successful application for the determination of Ch in two commercial pharmaceuticals.     

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.     

芯片毛细管电泳电化学检测

评述了芯片毛细管电泳各种电化学检测尤其是安培检测中工作模式、工作电极、分离电流的消除、应用等方面的进展,并进行了展望。     

毛细管电泳安培检测法测定密蒙花中的黄酮类化合物

采用毛细管电泳-安培检测法(CE-AD)对蒙花苷、刺槐素、木犀草素和芹黄素四种黄酮类化合物进行分离分析.在电极电位为+0.95 V(vs.Ag/AgCl),电泳运行液为pH=9.00的60 mmol/L Na2 B4O7-120 mmol/L NaH2 PO4缓冲溶液,分离电压为18kV时,四种黄酮类化合物得到完全分离...     

芯片毛细管电泳-安培检测系统

由于安培检测具有的高灵敏度、低成本、低能耗、易集成化便携化、与微加工技术匹配等特点,芯片毛细管电泳-安培检测系统（μCE-AD）的研究近年来得到人们广泛的关注。本文结合本课题组的研究工作,对近年来μCE-AD的研究进展进行评述;重点讨论了近年来在芯片的设计、集成化电极的制备、消除分离电压的干扰等方面的进展;同时介绍了利用分离电场拓展检测范围、阵列电极和阵列通道、化学修饰电极的应用、新型进样技术和试样预处理等方面的新成就;最后展望了未来μCE-AD的发展趋势。     

高效毛细管电泳的离柱安培法检测

设计了一种新型的毛细管电泳离柱安培法检测装置,无需截断毛细管,直接使用氢氟酸蚀刻毛细管管壁制作导电接口,可有效地耦合毛细管电泳分离和安培法检测,隔离高压电场对安培法检测的干扰,实现多组分的高效分离和检测。所设计的系统性能优良,导电接口制作简便,耐用性好,无附加体积。     

Determination of Glucose in Diluted Blood with a Thermal Flow Injection Analysis Biosensor

Abstract

The glucose concentration in diluted whole blood has been measured, using a miniaturized thermal biosensor based on the enzyme thermistor principle. The biosensor is a small flow injection system. A sample volume of 20μl is injected into a flow of 50μl/min. The heat produced when the sample passes the enzyme column is measured with a thermistor connected to a Wheatstone bridge. The enzyme column contains glucose oxidase and catalase co-immobilized on a solid support material. Samples of whole blood usually cause problems in flow-systems. The blood cells tend to block the enzyme column and the back pressure increases. We have tested a superporous agarose material as enzyme support material using tenfold diluted samples of whole human blood. The blood was collected from the finger-tip and diluted with buffer containing an anticoagulant and sodium fluoride. The number of samples possible to inject and the accuracy compared to the Boehringer Mannheim Reflolux have been determined. At least 100 ten-fold diluted blood samples could be injected on a micro-column of superporous agarose. The obtained glucose concentration correlated well with the one obtained with the reference instrument.     

Capillary Zone Electrophoresis of Eleven Priority Phenols with Amperometric Detection

A scheme for separation and detection of eleven priority phenols using capillary zone electrophoresis (CZE) coupled with amperometric detection is described. With a capillary of I.D. 50 μm and length 62.5 cm at 9 kV and an electrophoretic buffer of 20 mM CHES (pH 10.1), complete separation of the eleven compounds was achieved in less than 17 min. Amperometric detection was carried out using a carbon fiber microelectrode of diameter 9 μm inserted into the end of the detection capillary. Linearity over two orders of magnitude was generally obtained for the eleven priority phenols. With an electrode potential+1.10 V (vs. Ag/AgCl reference), the concentration limits of detection were in the sub-ppm (10^?6 M) level. This method was successfully applied to analysis of priority phenols in industrial waste water.     

毛细管电泳-柱端电化学检测池的设计

在射壁式检测器的基规上,设计了一种用于毛细管电泳-电化学检测装置的检测池,巧妙地利用因表面张力现象而留驻波滴曲面的放大作用,直接调整毛细管与电极之间的相对位置,无需显微镜-微调节器装置,具有空间体积小,操作更简便的优点。     

Simultaneous Determination of Catecholamines and Related Metabolites by Capillary Electrophoresis with Amperometric Detection

An electrophoretic method was developed for the determination of several important catecholamine markers, namely norepinephrine, epinephrine, dopamine, metanephrine, vanillylmandelic acid and homovanillic acid in urine samples. Under the optimum conditions, the six marker compounds could be well separated with the major coexisting interference compound uric acid within 24 min at a separation voltage of 16 kV in a borate running buffer (80 mmol/L, pH=9.48). Highly linear response can be obtained over three orders of magnitude for the above markers with the low limits of detection ranging from 1.0 ng/mL to 5.0 ng/mL(S/N=3). The proposed capillary electrophoresis with amperometric detection(CE-AD) method has been used to simultaneously determine the six catecholamine markers in urine samples of healthy volunteers and patients suffering from different diseases avoiding redundant measurements and high assay cost; and the electrochemical profiles can suggest more diagnostic information of multiple diseases, which provides a promising and convenient entry into primary diagnoses of several clinical diseases.     

毛细管电脉在柱安培检测信号的小波滤噪研究

采用一种新的小波滤噪方法对毛细管电泳在柱安培检测信号进行了处理,研究了小波基的选择、噪音在不同细节中的特征以及噪音阈值的确定等,用此方法对酚类定量分析,结果信噪比、检测限和线性范围均有较大改善。