A colorimetric chemosensor for sulfide in a near-perfect aqueous solution: practical application using a test kit

Abstract

A new highly selective colorimetric chemosensor 1 N′1-((E)-2,3-dihydroxybenzylidene)-N′2-((Z)-2,3-dihydroxybenzylidene)oxalohydrazide for S²⁻ was designed and synthesized. The sensor 1 showed a selective colorimetric sensing ability toward S²⁻ by changing color from colorless to yellow in a near-perfect aqueous solution. To understand the sensing mechanism of 1 with S²⁻, UV-vis spectroscopy, ESI-mass spectroscopy analysis and DFT calculations were carried out. Practically, sensor 1 functioned as a visible test strip for S²⁻. Moreover, the sensing ability of 1 for S²⁻ was successfully applied in real water samples. Therefore, sensor 1 could be a good alternative method for onsite and real time screening of S²⁻.