Fabrication of disposable ultramicroelectrodes: Characterization and applications

We report an easy method for fabricating disposable screen-printed edge band ultramicroelectrodes (designated as SPUMEs) with a built-in three-electrode pattern of alternating printed-layer of carbon, silver, and insulator on a non-conducting polypropylene substrate. Central idea is that the edge of the carbon and/or metal-sandwiched films between the insulator layers can serve as a band type ultramicroelectrode. Simply by slicing the edge of working window, the SPUME dimension can be easily varied (e.g., in the range of 0.18-1.35 mm length with a width of 20 mu m in this study). Cyclic voltammograms of ferricyanide in aqueous media displayed low-noise, low-background, sigmoidal responses with virtually no current hysteresis similar to that of a hemicylindrical electrode. The proposed SPUMEs exhibit very low electrical noise and can be reproduced multiple times by repetitively cutting the strip. Since they are cheap and easy for mass production, the disposable nature further offers to application in diverse field of electroanalytical chemistry. (c) 2006 Elsevier B.V. All rights reserved.