Fundamental studies of glucose oxidase deposition on a Pt electrode.
The direct electrodeposition of glucose oxidase (EC 1.1.3.4) on a platinum electrode was investigated as a means for controlled immobilization. The presence of a nonionic detergent, Triton X-100, was found essential to produce a multilayered deposit. Moreover, to work properly, the detergent must be present above its critical micelle concentration. Under these conditions, a deposit of approximately 50 enzyme layers (480 nm), with surface uniformity of +/-20 nm, was verified using an electrochemical quartz crystal microbalance and by atomic force microscopy. In the absence of detergent, a layer of 25 nm is formed. Contrary to most previous claims, the deposition, which is potential dependent but optimal at 1.3 V versus AgCl/Ag electrode, is not electrophoretically driven, but is instead controlled by a lowering of the pH at the electrode surface due to concomitant oxygen evolution.
Matsumoto
Norio
N
Department of Chemistry, University of Kansas, Lawrence 66045, USA.
Chen
Xiaohong
X
Wilson
George S
GS
D015374:Biosensing Techniques / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D010984:Platinum; D013499:Surface Properties
D004800:Enzymes, Immobilized; D010984:Platinum; D005949:Glucose Oxidase