A novel one-stepped synthesized Schiff-base fluorescence probe for specific recognition of zinc ions with highly sensitive and its application in living cells.

Fluorescent turn-on receptors are extensively employed for the detection of Zn ions contamination in the environment due to its simplicity, convenience and portability. However, developing highly sensitive and cell-imageable fluorescent turn-on probe for the recognition of Zn ions in living organisms remains a significant challenge. Herein, we have successfully synthesized a novel Schiff base probe (HL) with a significant fluorescence turn-on response (Zn ions) by one-step synthetic method. In this work, HL exhibited high sensitivity to Zn ions upon interaction with various common metal ions in HEPES buffer solution. Its detection limit is 1.87 × 10 M, which is lower than the requirement of Environmental Protection Agency (EPA) and World Health Organization (WHO) guidelines. The fluorescence titration and Job's plot analysis suggested a 1:1 binding ratio between the probe and Zn ion, and the single-crystal structures obtained further confirmed this inference. In addition, the fluorescent sensor demonstrated recyclability, maintaining its fluorescence intensity for up to 6 cycles without significant decrease, which holds promise for future investigations on reversible fluorescent chemosensors. Notably, fluorescence imaging experiments demonstrated that HL could be successfully used for the detection of Zn in live cells.