A novel dual-function bithiophene-Meldrum's acid based chemosensor for highly sensitive, colorimetric and fluorimetric detection of cyanide and hypochlorite and its applications

A dual-function bithiophene-Meldmm's acid based chemosensor 2TM was developed, which displayed ultrafast, colorimetric and fluorescence turn-on responses for CN- and ClO- with specific selectivity and high sensitivity. The sensor 2TM for CN- detection in DMSO/H2O (1/3, V/V) solution was based on the nucleophilic addition of CN- to sensor, which resulted in remarkable spectral and discernible color changes. Meanwhile, 2TM showed specific selectivity for ClO- in 100% aqueous solution based on the sensing mechanism of oxidative cleavage of C=C bond. The detection limits were obtained to be 0.96 mu M for CN- and 48 nM for ClO-. The sensing mechanism of 2TM toward CN- and ClO- was investigated by job'plot, FTIR, H-1 NMR, HRMS and optical spectra. The sensor 2TM loaded colorimetric test strips/supported silica measurements demonstrated to be a portable, eco-friendly and ultrafast device for real-time and on-site visual detection of CN- and ClO- in water by the naked eye. More importantly, sensor 2TM with excellent photophysical properties and low biotoxicity was successfully applied to detect CN- and ClO- in live cells and environmental water samples, as well as capable of monitoring CN- in the natural food samples, illustrating its practical utility in biological and environmental systems.