A near-infrared dual-channel fluorescent probe for ultrasensitive detection of Zn2+ and Cd2+ in food safety and bioimaging applications.

Accurate quantification of Zn2+ is crucial for food quality control and nutritional assessment, whereas sensitive detection of Cd2+ is vital for food safety assurance and aquatic environmental protection. Herein, we report the design and synthesis of DSYQ, a near-infrared (NIR) dual-channel fluorescent probe. DSYQ exhibits exceptional selectivity toward Zn2+ and Cd2+, producing distinct NIR fluorescence responses with large Stokes shifts. The probe demonstrates ultra-sensitive detection capabilities in complex food matrices. Moreover, DSYQ shows outstanding biocompatibility and versatile imaging capabilities, enabling the simultaneous real-time monitoring of endogenous Zn2+ fluctuations and exogenous Zn2+/Cd2+ uptake in 4T1 cells. In vivo experiments demonstrate its ability to track metal ion dynamics in tumor-bearing mouse models. Compared to existing methods, this probe integrates near-infrared emission, high sensitivity, and a large Stokes shift, allowing it to effectively address complex practical application requirements. However, further validation and field-level evaluation are still required for routine deployment.