Four Xanthene-fluorene based probes for the detection of Hg2+ ions and its application in strip test and biological cells

Four new xanthene-based fluorescent probes have been devised and synthesized. These probes were well characterized by 1H NMR, 13C NMR and HRMS. The UV-vis absorption and fluorescence spectroscopy indicated that these probes all show high selectivity and sensitivity towards Hg2+ in the presence of various cations，anions and amino acids in PBS buffer solution containing DMSO/H2O (1:1, v/v). The detection limit of the probes for Hg2+ were found to be 10.4 nM, 12.5 nM, 16.2 nM and 15.4 nM, respectively. Four probes were successfully applied for the detection of Hg2+ in strip test. Among them, the Probe 4 was successfully applied for the detection of Hg2+ in biological cells.