Parra A, Casero E, Vázquez L, Jin J, Pariente F, Lorenzo E
Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Campus de Cantoblanco, 28049 Madrid, Spain.
Langmuir. 2006 Jun 6;22(12):5443-50. doi: 10.1021/la060184g.
A microscopic and voltammetric characterization of lactate oxidase- (LOx-) based bioanalytical platforms for biosensor applications is presented. In this context, emphasis is placed on amperometric biosensors based on LOx that have been immobilized by direct absorption on carbon surfaces, in particular, glassy carbon (GC) and highly ordered pyrolytic graphite (HOPG). The immobilized LOx layers have been characterized using atomic force microscopy (AFM) under liquid conditions and cyclic voltammetry. In addition, spatially resolved mapping of enzymatic activity has been carried out using scanning electrochemical microscopy (SECM). In the presence of lactate with hydroxymethylferrocene (HMF) as a redox mediator in solution, biosensors obtained by direct adsorption of LOx onto GC electrodes exhibited a clear electrocatalytic activity, and lactate could be determined amperometrically at 300 mV versus SSCE. The proposed biosensor also exhibits good operating performance in terms of linearity, detection limit, and lifetime.
本文介绍了用于生物传感器应用的基于乳酸氧化酶（LOx）的生物分析平台的微观和伏安特性。在此背景下，重点关注基于LOx的电流型生物传感器，这些传感器通过直接吸附固定在碳表面，特别是玻碳（GC）和高度有序热解石墨（HOPG）上。已使用液体条件下的原子力显微镜（AFM）和循环伏安法对固定化的LOx层进行了表征。此外，还使用扫描电化学显微镜（SECM）对酶活性进行了空间分辨映射。在溶液中存在乳酸并以羟甲基二茂铁（HMF）作为氧化还原介质的情况下，通过将LOx直接吸附到GC电极上获得的生物传感器表现出明显的电催化活性，并且可以在相对于饱和甘汞电极（SSCE）为300 mV的电位下通过安培法测定乳酸。所提出的生物传感器在线性、检测限和寿命方面也表现出良好的操作性能。
