Campuzano S, Gamella M, Serra B, Reviejo A J, Pingarrón J M
Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, E-28040 Madrid, Spain.
J Agric Food Chem. 2007 Mar 21;55(6):2109-14. doi: 10.1021/jf063073w. Epub 2007 Feb 27.
An integrated amperometric gluconic acid biosensor constructed using a gold electrode (AuE) modified with a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA) on which gluconate dehydrogenase (GADH, 0.84 U) and the mediator tetrathiafulvalene (TTF, 1.5 micromol) were coimmobilized by covering the electrode surface with a dialysis membrane is reported. The working conditions selected were Eapp=+0.15 V and 25+/-1 degrees C. The useful lifetime of one single TTF-GADH-MPA-AuE was surprisingly long. After 53 days of continuous use, the biosensor exhibited 86% of the original sensitivity. A linear calibration plot was obtained for gluconic acid over the 6.0x10(-7) to 2.0x10(-5) M concentration range, with a limit of detection of 1.9x10(-7) M. The effect of potential interferents (glucose, fructose, galactose, arabinose, and tartaric, citric, malic, ascorbic, gallic, and caffeic acids) on the biosensor response was evaluated. The behavior of the biosensor in a flow-injection system in connection with amperometric detection was tested. The analytical usefulness of the biosensor was evaluated by determining gluconic acid in wine and must samples, and the results obtained were validated by comparison with those provided by using a commercial enzyme test kit.
报道了一种集成式安培型葡萄糖酸生物传感器，该传感器采用金电极（AuE）构建，金电极上修饰有3-巯基丙酸（MPA）的自组装单分子层（SAM），通过用透析膜覆盖电极表面将葡萄糖酸脱氢酶（GADH，0.84 U）和媒介体四硫富瓦烯（TTF，1.5 μmol）共固定在其上。选择的工作条件为Eapp = +0.15 V和25±1℃。单个TTF-GADH-MPA-AuE生物传感器的使用寿命出奇地长。连续使用53天后，该生物传感器仍表现出原始灵敏度的86%。在6.0×10⁻⁷至2.0×10⁻⁵ M的葡萄糖酸浓度范围内获得了线性校准曲线，检测限为1.9×10⁻⁷ M。评估了潜在干扰物（葡萄糖、果糖、半乳糖、阿拉伯糖以及酒石酸、柠檬酸、苹果酸、抗坏血酸、没食子酸和咖啡酸）对生物传感器响应的影响。测试了该生物传感器在与安培检测相关的流动注射系统中的性能。通过测定葡萄酒和葡萄汁样品中的葡萄糖酸来评估该生物传感器的分析实用性，并将所得结果与使用商业酶测试试剂盒得到的结果进行比较以进行验证。
