An efficient and sensitive chemosensor based on salicylhydrazide for naked-eye and fluorescent detection of Zn²

We reported here the synthesis of a diarylethene with a 2,4-dihydroxybenzoyl hydrazine moiety (1O) for Zn²⁺ recognition. The compound is easy to prepare with a high yield up to 85%. Compound 1O can act as a highly selective and specific fluorescent sensor for Zn²⁺ without interference by other common metal ions. The LOD for Zn²⁺ detection was determined to be 1.28 × 10^-6 mol L^-1. Meanwhile, 1O can be used as a naked-eye detector for the Zn²⁺ ion with an obvious color change from colorless to olive. Based on the fluorescent properties of 1O, we constructed a logic circuit with four inputs of the combinational stimuli of UV/vis light and Zn²⁺/EDTA, and one output of fluorescence intensity.