CELLOBIOSE OXIDASE CROSS-LINKED IN A REDOX POLYMER MATRIX AT AN ELECTRODE SURFACE - A NEW BIOSENSOR
CELLOBIOSE OXIDASE CROSS-LINKED IN A REDOX POLYMER MATRIX AT AN ELECTRODE SURFACE - A NEW BIOSENSOR
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DOI：
10.1016/0022-0728(92)80487-o
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发表时间：
1992-12-10
影响因子：
4.5
通讯作者：
HENRIKSSON, G
中科院分区：
文献类型：
--
作者：
ELMGREN, M;LINDQUIST, SE;HENRIKSSON, G
研究了以纤维素二糖氧化酶（CBO）为基础，在旋转圆盘电极上交联氧化还原聚合物（聚（乙烯基吡啶）Os(bpy)2Cl2+/3+]/多胺）为基体的酶电极的性能。考察了pH、温度、转速和膜厚对纤维素糖稳态响应的影响。不管膜厚度至少达到2.5 μ m，可达氧化还原偶的百分比保持不变，这表明酶-聚合物基质的最外层完全可达。表观米歇里斯常数K(m)'随着薄膜厚度的增加而增加，这是由于薄膜中衬底的损耗所致。随着膜厚度的增加，周转数k2′减小，表明电荷通过膜传播导致反应受限。外推到一个无限小的膜，电极的动力学常数反映了溶液中的酶动力学。最厚电极的Arrhenius活化能为42 kJ mol-1，最薄电极的Arrhenius活化能为34 kJ mol-1。该电极适用于纤维二糖、乳糖和麦芽糖以及纤维三糖和相应的低聚糖的传感器，聚合度至少为6。
The properties of an enzyme electrode, based on cellobiose oxidase, CBO, crosslinked in a redox polymer (poly[(vinylpyridine)Os(bpy)2Cl2+/3+]/polyamine) matrix on a rotating disk electrode were studied. Effects on the steady state cellobiose response of pH, temperature, rotation rate and film thickness were investigated. The percentage of accessible redox couples remained constant, regardless of film thickness up to at least 2.5 mum, indicating full access to the outermost layer of the enzyme-polymer matrix. The apparent Michaelis constant K(m)' increased with increasing film thickness, owing to depletion of substrate in the film. The turnover number k2' decreased with increasing film thickness, indicating reaction limitation due to charge propagation through the film. Extrapolated to an infinitesimal film, the kinetic constants of the electrode mirror the enzyme kinetics in solution. The Arrhenius activation energy was determined to be 42 kJ mol-1 for the thickest electrode and 34 kJ mol-1 for the thinnest. The electrode is suited as a sensor for cellobiose, lactose and maltose as well as for cellotriose and corresponding oligosaccharides up to a degree of polymerization of at least six.