A diarylethene-based “on–off–on” fluorescence sensor for the sequential recognition of mercury and cysteine

Abstract

A novel photochromic diarylethene with a quinoline unit was synthesized with multi-controllable fluorescence switching properties, which could be induced by light, mercury (Hg²⁺) and cysteine (Cys). Because the diarylethene displayed obvious fluorescence quenching with Hg²⁺ and the fluorescence was recovered to its original state evidently with Cys, it could sequentially recognize Hg²⁺ and Cys. Additionally, a logic circuit was constructed with the fluorescence intensity at 468 nm as output, and the combined stimuli of light and chemicals as inputs.