An innovative fluorescent probe based on 1,8-naphthalene dicarboxylic anhydride for Zn2+ detection, its application in food analysis and bioimaging

Zinc is one of the essential trace elements in the human body and plays an extremely important role in physiological processes. Therefore, it is necessary to develop a detection method that can be used for real-time, highly sensitive response of Zn2+ in organisms and has low toxicity. In this work, a novel fluorescent probe NA for Zn2+ detection based on 1,8-naphthalene dicarboxylic anhydride and dimethylpyridine amine was synthesized. Probe NA has specific recognition and real-time monitoring functions for Zn2+. Based on Job's plotting curve, it is inferred that the coordination ratio between probe NA and Zn2+ is 3:1, forming a complex of [Zn(NA)3]2+. The [Zn(NA)3]2+ exhibits obvious yellow fluorescence at 550 nm. Probe NA can achieve quantitative detection of Zn2+ with a detection limit of 7.52 × 10−9 M, with high selectivity and anti-interference ability. Probe NA can stably exist in a wide pH range (2–10). This indicates that it can detect Zn2+ in complex environments. In addition, based on the low cytotoxicity, high sensitivity, and real-time monitoring characteristics of probe NA, we have expanded it to real-time monitoring of Zn2+ in organisms (HUVEC cells and live mice), as well as qualitative and quantitative detection of Zn2+ concentration in food and drugs.