Potential Response of Monolayer-Modified Indium Tin Oxide Electrodes to Indole Compounds

Potential response of indium tin oxide (ITO) electrode modified by treatment with disuccinimidyl suberate (DSS) was investigated to various target molecules. Distinctively, the DSS-modified ITO electrode exhibited a potential shift to the molecules possessing an indole group such as tryptophan, tryptamine and indole propionic acid, while little response to benzoic acid, phenylalanine, proline, proline amide, and arginine was observed. In addition, the combination of this specificity to indoles and enantioselective affinity of human serum albumin (HSA), which was additionally immobilized on the DSS-modified ITO electrode, brought about enantioselective potential response to tryptophan.