A near-infrared fluorescent probe to detect CN^- in high-water-content systems and its bioimaging applications

CN^- poses severe threats to environmental and biological health. In this study, we developed a novel near-infrared fluorescent probe named AMZ, which exhibits high selectivity for CN^- in tetrahydrofuran solution containing 90 % water. AMZ demonstrates an "on-off" response, with maximum excitation at 458 nm and maximum emission at 686 nm. AMZ offers advantages such as a simple synthesis process, strong anti-interference ability, and an ultra-low LOD (1.69 × 10^-11 M). The recognition mechanism was systematically studied using spectroscopic techniques, including ¹H NMR titration, UV-Vis, fluorescence spectroscopy, FT-IR, and HR-MS. To broaden its applications, we developed an AMZ-based test strip for rapid and sensitive qualitative and semi-quantitative detection. Furthermore, AMZ successfully enabled rapid detection of endogenous and exogenous cyanide in almonds. Additionally, AMZ demonstrated excellent bioimaging capabilities in plant sprouts, nematodes, and mice, facilitating real-time monitoring of CN^- distribution. These results highlight AMZ as an efficient, versatile tool for environmental monitoring, food safety testing, and biomedical research.