A highly sensitivity fluorescent probe based on rhodamine for naked-eye detection of Hg2+ in aqueous solution

In this study, we have successfully synthesised a novel fluorescent chemosensor TM using rhodamine as the fluorophore and 8-hydroxyquinoline as recognition group through traditional Schiff base preparation methods. The chemical structure of sensor TM was characterised by 1H NMR, 13C NMR and ESI-MS. Sensor TM showed obvious fluorescence enhancement response to Hg2+ ion. The detection limit was 0.05 μM, and the solution colour changed from colourless to pink, making it a promising probe for effective naked-eye detection of Hg2+. The results of Job curve indicated that sensor TM and Hg2+ ion coordinated with each other with a binding stoichiometry of 1:1, and the pH test results showed that sensor TM was only suitable for acidic and neutral conditions.