A highly sensitive polydentate ligand-based fluorescent probe for imaging of Hg2+ in Arabidopsis thaliana

Abstract

A novel fluorescent chemosensor (E)-2-((3-((bis(pyridin-2-ylmethyl)amino)methyl)-2-hydroxy-5-methylbenzylidene)amino)-3′, 6′-bis(diethylamino)spiro[isoindoline-1, 9′-xanthen]-3-one (RPA) was synthesized through traditional Schiff base preparation methods and characterized by ¹H NMR, ¹³C NMR and ESI-MS. Sensor RPA showed obvious fluorescence enhancement response to Hg²⁺ in aqueous solution, and the detection limit was 0.8 μM. The results of Job curve indicated that sensor RPA and Hg²⁺ ion coordinated with each other with a binding stoichiometry of 1:1, and the optimal pH range was from 4 to 9. The results of paper strip suggested that sensor RPA could been used for effective naked-eye detection of Hg²⁺ and showed low toxicity and good biocompatibility with Arabidopsis thaliana.