A new thiophene-based dual functional chemosensor for ultrasensitive colorimetric detection of Cu2+ in aqueous solution and highly selective fluorimetric detection of Al3+ in living cells

Abstract

A new thiophene-based colorimtric and fluorimetric dual functional sensor TSA was synthesized, which can highly sense Al3+ and Cu2+ ions in aqueous solution through two approaches: a significant fluorescence enhancement caused by Al3+ and a visible color change from colorless to yellow induced by Cu2+. The sensor TSA showed a highly binding affinity only toward Al3+ and Cu2+ even in the presence of other competitive metal ions with low detection limits of 49 nM and 0.217 μM, respectively. The mechanisms of TSA for sensing Al3+ and Cu2+ were based on the metal ions coordination of TSA, which have been demonstrated by HR ESI-MS and 1H NMR titration. In addition, sensor TSA was successfully applied to quantify Al3+ and Cu2+ in environmental water and food samples with good precision and accuracy. Moreover, the TSA-based test stips/silica can conveniently and practically detect and discriminate Al3+ and Cu2+ in water. Furthermore, sensor TSA has also been applied to detect Al3+ in live HeLa cells. This work provides a new approach with easily synthetic route and economically cheap for ultrasensitive, selective, quantitative and differentiable detection of Al3+ and Cu2+ in environmental, food and biological systems.