PEDOT:PSS-modified TiO2 electrode for photoelectrochemical microscopy

Abstract Photoelectrochemical microscopy provides a label-free approach to visualize redox-active species. In this study, an electrochemical imaging system was developed using nanostructured titanium dioxide films prepared on fluorine-doped tin oxide substrates. The electrodes were modified with the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) to enhance interfacial charge transfer efficiency. PEDOT:PSS modification significantly increased the photocurrent (∼120 nA), and further enhancement (∼160 nA) was achieved through DMSO treatment. The platform enables simple, current-based imaging without the need for complex wiring or scanning probes.