Scanning Electrochemical Microscopy. 17. Studies of Enzyme-Mediator Kinetics for Membrane= and Surface- Immobilized Glucose Oxidase

The scanning electrochemical microscope (SECM) can be used to detect electron-transfer reactions of tlp-generated species that occur at nonconductlve surfaces contalnlng a redox-actlve enzyme. Experlments were carrkd out wlth glucose oxldase lmmoblilzed on several substrates and the apparent kinetics of the enzyme catalyds were measured for several medlator oxldants under condltlons of hlgh pgiucose concentration. Theory for the SECM feedback current was developed to model the llmltlng zero- and flrst-order eiectrontransfer klnetlcr expected for such surface catalyds. Working curves relatlng the SECM feedback current to surface rate constants are presented. For Substrates wlth glucose OXC dam covalently attached to the surface or trapped wlthln a porous membrane, the enzyme reactlon was readlly detected and the SECM feedback currents measured at low mediator concentration (ca. 50 pM) were found to excluslvely flt the model for zeroorder heterogeneous kinetlcs. However, at low enzyme surface concentratlon or wlth extendve chemlcal crorrJinklng of immoblllzed glucose oxidase, It was very difficult to use the SECM to detect and quanttfy the enzyme reactlon. General guideilnes for studylng enzyme surface reactions with the SECM are given, and the prospects for detecting and klneticaily assaying enzymes of cellular, and even subcellular, samples are discussed.

[1]  A. Bard,et al.  Scanning electrochemical microscopy. 16. Study of second-order homogeneous chemical reactions via the feedback and generation/collection modes , 1992 .

[2]  A. Bard,et al.  Scanning electrochemical microscopy. 14. Scanning electrochemical microscope induced desorption: A new technique for the measurement of adsorption/desorption kinetics and surface diffusion rates at the solid/liquid interface , 1992 .

[3]  A. Bard,et al.  Chemical Imaging of Surfaces with the Scanning Electrochemical Microscope , 1991, Science.

[4]  A. Bard,et al.  Scanning Electrochemical Microscopy VII . Effect of Heterogeneous Electron‐Transfer Rate at the Substrate on the Tip Feedback Current , 1991 .

[5]  Adam Heller,et al.  Redox polymer films containing enzymes. 2. Glucose oxidase containing enzyme electrodes , 1991 .

[6]  C. Goss,et al.  Application of (3-mercaptopropyl)trimethoxysilane as a molecular adhesive in the fabrication of vapor-deposited gold electrodes on glass substrates , 1991 .

[7]  A. Bard,et al.  Scanning electrochemical microscopy. 9. Theory and application of the feedback mode to the measurement of following chemical reaction rates in electrode processes , 1991 .

[8]  Guy Denuault,et al.  Scanning electrochemical microscopy - a new technique for the characterization and modification of surfaces , 1990 .

[9]  A. Bard,et al.  Scanning electrochemical microscopy. Application to polymer and thin metal oxide films , 1990 .

[10]  I. Karube,et al.  Kinetics of an amperometric glucose sensor with a soluble mediator , 1989 .

[11]  A. Bard,et al.  Scanning electrochemical microscopy. Apparatus and two-dimensional scans of conductive and insulating substrates , 1989 .

[12]  T. Kuriyama,et al.  Evaluation of an albumin-based, spin-coated, enzyme-immobilized membrane for an isfet glucose sensor by computer simulation , 1989 .

[13]  A. Bard,et al.  Scanning electrochemical microscopy. Theory of the feedback mode , 1989 .

[14]  M. Senda,et al.  Theory of Catalytic Current at the Biocatalyst Electrode with Entrapped Mediator , 1988 .

[15]  L. B. Wingard,et al.  Mass transport and reaction kinetic parameters determined electrochemically for immobilized glucose oxidase. , 1984, Biochemistry.

[16]  G. S. Wilson,et al.  Rotating ring-disk enzyme electrode for surface catalysis studies. , 1976, Analytical chemistry.

[17]  D. Morris,et al.  The preparation of nylon-tube-supported hexokinase and glucose 6-phosphate dehydrogenase and the use of the co-immobilized enzymes in the automated determination of glucose. , 1975, The Biochemical journal.