A novel hydrazide-based fluorescent chemosensor and its application to recognize Cu2+ and glyphosate in environmental and biological systems

Background Although copper ions (Cu 2+ ) and glyphosate (GLY) tend to exist in the environment or living organisms at low doses, they gradually accumulate with exposure time and may eventually cause irreversible damage to living organisms. The existing detection methods are effective, but most of them lack the ability to detect multiple pollutants simultaneously or suffer from low sensitivity and poor selectivity. Therefore, it is important to develop a sensor that can efficiently and sensitively detect copper ions and glyphosate, but also has the potential for practical applications. Results In this study, a novel hydrazide-based DHBC capable of sequentially detecting Cu 2+ and glyphosate (GLY) was developed. The DHBC forms a complex with Cu 2+ , causing fluorescence quenching. Upon exposure to GLY, functional groups such as carboxyl, phosphate, and amino groups coordinate with Cu 2+ , displacing DHBC and restoring fluorescence intensity. The mechanism has been validated by various characterization methods such as HRMS and Job curves, DFT calculation, etc. The DHBC has excellent detection performance, including high selectivity, strong anti-interference, fast response (less than 1 min), and high sensitivity (Cu 2+ : 0.09 μM, GLY: 0.05 μM). The quantitative analysis of Cu 2+ /GLY in cycling experiments and actual samples demonstrated the great potential of DHBC for practical applications. The DHBC successfully imaged Cu 2+ /GLY in live models such as HeLa cells and zebrafish, demonstrating its broad applicability and stability in a wide range of biological models. Significance The high accuracy of DHBC in environmental pollution monitoring and its stable performance in biological modeling make it an important tool for assessing the impact of pollutants on ecosystems and human health. In addition, the wide applicability and real-time imaging capability of DHBC provide reliable technical support for environmental science, toxicology, and health risk assessment and have important prospects for scientific research and practical applications.