期刊
ANALYTICAL CHEMISTRY
卷 75, 期 9, 页码 2060-2064出版社
AMER CHEMICAL SOC
DOI: 10.1021/ac020765k
关键词
-
资金
- NIGMS NIH HHS [GM 08194] Funding Source: Medline
A direct ionotropic gelation of the polycationic biopolymer chitosan (CHIT) with the polyanionic enzyme lactate oxidase (LOx) was used to form thin biopolymer-enzyme films on the surface of platinum electrodes. The electrochemical assays of such films revealed a well-defined capacity of CHIT for the retention of LOx. The stoichiometry of the CHIT-LOx polyelectrolyte complexes was found to be similar to1:40, i.e., on average, 1 CHIT chain retained 40 molecules of LOx in the CHIT-LOx films. The enzyme retention was ascribed to strong electrostatic interactions between the LOx and a fraction of the protonated amino groups on the CHIT chains. Although the LOx is inherently unstable outside its natural matrix, it displayed high surface activity of 0.26 units cm(-2) in the matrix of CHM This correlated with good stability of the biopolymer-enzyme films as demonstrated by a constant response of Pt/CHIT-LOx electrodes to lactate during continuous 24-h testing. When compared to other single-film lactate sensors, the Pt/CHIT-LOx electrodes displayed the best combination of analytical properties in terms of a low detection limit (50 nM), high sensitivity (0.23 A M-1 cm(-2)), and fast response time (< 1 s). Such a performance validated the CHIT-LOx system as an attractive sensing element for the development of new lactate biosensors.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据