Highly selective and sensitive colorimetric chemosensor for detection of Co2+ in a near-perfect aqueous solution

Abstract

A new simple and easy-to-make colorimetric chemosensor 1 was designed and synthesized by combination of 4-diethylaminosalicylaldehyde and diethylenetriamine. In a near-perfect aqueous solution, sensor 1 showed a selective color change from colorless to yellow in the presence of Co²⁺ with a 1 : 1 stoichiometric system. To investigate the sensing mechanism of 1 for Co²⁺, UV-vis spectroscopy, ESI-mass and theoretical calculations were conducted. The detection limit (0.65 μM) of 1 for Co²⁺ was comparable to the Federal-State Toxicology and Risk Analysis Committee (FSTRAC) guideline in drinking water (0.68 μM). Practically, 1 functioned as a visible test strip with a silica plate and could be used to quantify Co²⁺ in real water samples. Therefore, probe 1 could be a good alternative method for on-site and real time screening of Co²⁺.