Indium Tin Oxide Nanoparticle-modified Glassy Carbon Electrode for Electrochemical Sulfide Detection in Alcoholic Medium.

An electrochemical sensor based on an indium tin oxide nanoparticle (ITONP)-modified glassy carbon electrode (ITONP/GCE) was developed for the detection of sulfides in alcoholic medium. The ITONP/GCE was prepared by simply dropping the aqueous solution of ITONP on the GCE surface and then drying at 40°C. The homogeneous distribution of ITONP on the GCE surfaces was confirmed by recording the camera photographs and field emission scanning electron microscopic images. The ITONP/GCE was further characterized with energy dispersive X-ray spectrometry, X-ray photoelectron spectroscopy and X-ray diffractometry to identify the surface chemical composition and crystallinity. The ITONP/GCE showed much better electrocatalytic properties toward sulfide electro-oxidation than that of bare GCE electrodes. The obtained amperometric detection limit of sulfide in alcoholic solutions of sodium acetate was 0.3 μM. The enhanced sensitivity, good selectivity and high stability are promising features of the ITONP/GCE for sulfide sensing.