A fluorescent probe for Hg2+ sensing in solutions and living cells with a wide working pH range

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 Hg2+ 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.

Graphical abstractA novel fluorescence turn-on probe for Hg2+ with a wide working pH range based on 2-carboxybenzaldehyde rhodamine B thiohydrazine was rationally designed and employed in the detection of Hg2+ in solutions and living cells.Figure optionsDownload full-size imageDownload as PowerPoint slide