Effects of chemical treatment of indium tin oxide electrode on its surface roughness and work function

In this paper, we report the effects of chemical treatment of indium tin oxide (ITO) surface on its surface chemistry such as chemical composition and surface roughness and on its usage as an electrode with monolayer modification. Atomic force microscopy, angel-resolved X-ray photoelectron spectroscopy, and Kelvin probe force microscopy have been used to investigate the morphology and the chemical properties of commercial thin ITO films after several treatments commonly used prior to the formation of organic layer on the surface. The amount of spike present on the surface of as-received ITO substrates was significantly reduced by etching with KOH whereas the roughness of ITO increased with HCl etching. We demonstrated that the successive treatment of ITO electrode with HCl and KOH affects the surface characteristics such as roughness and work function, contributing to the potentiometric detection of tryptophan.