Dual-Response Fluorescent Probe for Simultaneously Detecting HOCl and Zn2+ in Environmental Water Samples and Evaluating the Oxidative Stress in the Zebrafishes Induced by Pollutions via Fluorescence Imaging

Both of hypochlorous acid (HOCl) and Zn2+ ions play important roles in fundamental biological processes. They not only simultaneously exist in the biological organisms, but also coexist in the environment. Thus, developing a novel method for simultaneous detection of HOCl and Zn2+ is very necessary. Herein, the nitrogen- and sulfur-codoped carbon dots (N,S-CDs) were synthesized through a simple and rapid microwave method, it emits dual-emission fluorescence centered at 452 nm and 685 nm, which has specific recognition to HOCl and Zn2+, respectively, and they do not interfere with each other. A dual-emission and dual-response fluorescent probe was thus developed for the simultaneous detection of HOCl and Zn2+ in the environment and fluorescence imaging in the zebrafishes. The limits of detection for HOCl and Zn2+ are 27.0 nM and 13.0 nM, respectively. It has been successfully applied for the simultaneous determination of HOCl and Zn2+ in real water samples. The sensing mechanisms of the N,S-CDs to HOCl and Zn2+ were also discussed in detail. Moreover, the fluorescent probe not only can be used to real-time dynamic monitoring of HOCl and Zn2+ in the zebrafishes, but also can be applied to evaluate the oxidative stress in the zebrafishes induced by pollutions via fluorescence imaging. This work provided a new strategy for developing multifunctional fluorescence probes, and a potential application prospect for environmental monitoring and evaluating the health risks of environmental pollutants to organisms.