In this paper, 2-carboxybenzaldehyde rhodamine B thiohydrazine （1） was synthesized and developed as a fluorescent probe to recognize Hg2＋ in DMF/H2O （1：9, v/v） solution with high selectivity. The probe can be applied to the quantification of rig2＋ with a linear concentration range covering from 1.0 × 10^-7 mol/L to 1.0 × 10^-5 mol/L （R2 = 0.9985） and a detection limit of 4.2 × 10^-8 mol/L. The experiment results show that the response of probe 1 to Hg2＋ is pH-independent in a wide range from 4.0 to 9.0. Moreover, the probe 1 exhibits excellent selectivity toward Hg2＋ over other common metal cations. Most importantly, the probe can be employed to monitor Hg2＋ in living cells using fluorescent imaging technique with satisfied results.
