FLUORESCENT MICROPATTERN FORMATION ON IONIC CONDUCTIVE POLYMER-FILMS BY A SCANNING ELECTROCHEMICAL MICROSCOPE

An ionic conductive polymer film containing a fluorescent dye (rhodamine 6G; R-6G) and a fluorescent quencher (methylviologen; MV2+), coated on a platinum (Pt) substrate (counter electrode), was scanned by a negatively biased tungsten tip (working electrode) of a scanning electrochemical microscope (SECM). Although fluorescence of R-6G in the film is completely quenched by MV2+, scanning of the tungsten tip on the film at the bias voltage of -4.0 V led to recovery of R-6G fluorescence due to electrochemical decomposition of MV2+ at the tip/film interface, and therefore, to form a fluorescent micropattern on the film. The best resolution of the fluorescent micropattern was obtained to be less than 0.5-mu-m.