Microfabrication and Characterization of Diaphorase-Patterned Surfaces by Scanning Electrochemical Microscopy

Scanning electrochemical microscopy (SECM) was used to microfabricate and quantify diaphorase-pattemed glass surfaces. Deactivated circular and linear micropattems were produced at diaphorase-immobilized substrates by a localized surface reaction. The oxidation of Br^- and Cl^- at a microelectrode generated a reactive species which deactivated the localized enzyme molecules at the substrate. The diaphorase-patterned surfaces were characterized by SECM on the basis of detection of catalytic current of ferrocenylmethanol coupled with oxidation of NADH. The concentration of the immobilized diaphorase was mapped from the quantitative analysis of the catalytic current.