title: A laser ablation method for the spatial segregation of enzyme and redox sites on carbon fiber microelectrodes.
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.
authors.affiliation: Department of Chemistry, University of California, Riverside 92521, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Rosenwald
authors.forename: N
authors.initials: N
authors.lastname: Dontha
authors.forename: W G
authors.initials: WG
authors.lastname: Kuhr
mesh_terms: D015374:Biosensing Techniques; D002244:Carbon; D004798:Enzymes / Q000032:analysis*; D007700:Kinetics; D007834:Lasers; D008839:Microelectrodes; D008856:Microscopy, Fluorescence; D010084:Oxidation-Reduction
chemical_list: D004798:Enzymes; D002244:Carbon