A reversible and ratiometric fluorescent probe based on rhodol derivative with an ESIPT unit for monitoring copper ion content and in situ evaluation of related drugs in cells

The amount of copper ions in the environment has an immediate effect on ecology and food safety, Menkes syndrome and Wilson's disease cause accumulation and deficiency of copper ions in the body, respectively, and neurodegenerative diseases are also closely related to copper ion levels. However, the current copper ion detection technology has a high cost, complex operation, and other disadvantages. In this study, a ratiometric fluorescent probe (RB-DH) was rationally constructed to detect copper ions by coupling benzothiazole to rhodol derivatives. It can be used to determine copper ion concentrations in water samples, agricultural products, cells, and zebrafish. Importantly, due to the reversible response of RB-DH to copper ions, the fluctuation of intracellular copper ion content during the release of copper ion-related drugs (Copper gluconate and D-penicillamine) was successfully monitored with RB-DH for the first time. This study demonstrates RB-DH’s potential application in the evaluation of related drug release effects and serves as a guide for the establishment of portable detection techniques for other important substances.