Simultaneous Detection of Cu ²⁺ and Co ²⁺ by a Water‐Soluble Carboxamide‐Based Colorimetric Chemosensor

Abstract

Abstract A novel carboxamide‐based colorimetric chemosensor ATA‐Msal ((E)‐3‐((2‐hydroxy‐3‐methoxybenzylidene)amino)thiophene‐2‐carboxamide) for detecting Cu 2+ and Co 2+ in aqueous solution was synthesized. Sensor ATA‐Msal could probe Cu 2+ and Co 2+ by color change from colorless to pale yellow. According to results of Job plot and ESI‐mass, the binding modes of ATA‐Msal to Cu 2+ and Co 2+ were determined to be a 1 : 1 ratio. The detection limits (0.14 μM and 0.88 μM) of ATA‐Msal for Cu 2+ and Co 2+ were much lower than WHO standard (31.5 μM for Cu 2+ ) and US Environmental Protection Agency (EPA) standard (1.70 μM for Co 2+ ). ATA‐Msal can be applicable to real samples and test strips, and F − could be used to distinguish between ATA‐Msal ‐Cu 2+ and ATA‐Msal ‐Co 2+ . The sensing process of Cu 2+ and Co 2+ by ATA‐Msal was demonstrated by UV‐vis titration, ESI‐mass, EPR, 1 H NMR titration, and DFT.