A laser ablation method for the spatial segregation of enzyme and redox sites on carbon fiber microelectrodes

Anal Chem. 1998 Mar 15;70(6):1133-40. doi: 10.1021/ac970801t.

Abstract

A laser-generated interference pattern was used to remove enzyme from micrometer-wide stripes on an enzyme-covered carbon fiber microelectrode surface to create regions of facile electron transfer. Fluorescence microscopy was used to visualize fluorophore-tagged enzyme to indicate where the adsorbed enzyme remained on the surface. The electrochemical kinetics of the carbon fiber surface were examined to see if electron-transfer sites could indeed be segregated from enzyme adsorbed across the entire surface. CCD imaging of the electrochemical luminescence of Ru(bpy)3(2+) was used to verify the segregation between photoablated sites (with facile electron-transfer kinetics) and surfaces with adsorbed enzyme (which exhibit slow electron-transfer kinetics). The laser-ablated surface could also be distinguished from the enzyme-covered carbon surface with atomic force microscopy. Thus, photoablation of the surface of a protein-covered carbon fiber microelectrode with an interference pattern generated by a Nd:YAG laser allows the activation of 1.7-micron-wide bands of the electrode surface (available for facile electron transfer) while leaving 2.6-micron-wide enzyme-modified areas intact, thereby producing electroactive regions directly adjacent to enzyme modified regions of the same surface.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Biosensing Techniques*
  • Carbon
  • Enzymes / analysis*
  • Kinetics
  • Lasers
  • Microelectrodes*
  • Microscopy, Fluorescence
  • Oxidation-Reduction

Substances

  • Enzymes
  • Carbon