title: Characteristics of fast mediated bioelectrocatalytic reaction near microelectrodes.
abstract: The pseudo-steady-state current due to a mediated enzymatic reaction on a microelectrode is characterized on the basis of theoretical analysis and numerical simulation. The steady-state current is proportional to substrate concentration when the enzymatic reaction is considerably faster than substrate mass transport via nonlinear diffusion. Under such conditions, the reaction plane, where the mass flow of the substrate is converted to that of the mediator, exists near the electrode surface. The steady-state current increases as the diffusion coefficient of the substrate increases. In contrast, the diffusion coefficient and the concentration of the mediator have minor effects on the current. This difference can be explained on the basis of a change in the reaction plane location. When a sufficient amount of enzyme exists in a system, the system can be used as an amperometric biosensor, the response of which is independent of any change in enzyme activity.
authors.affiliation: Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto 606-8502, Japan. kitazumi.yuki.7u@kyoto-u.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kitazumi
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Noda
authors.forename: Osamu
authors.initials: O
authors.lastname: Shirai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Kano
mesh_terms: D055162:Biocatalysis; D015374:Biosensing Techniques; D004058:Diffusion; D004798:Enzymes / Q000737:chemistry / Q000378:metabolism*; D008839:Microelectrodes; D009716:Numerical Analysis, Computer-Assisted
chemical_list: D004798:Enzymes