A fluorescent turn-on probe for Hg(II) based on an NTe2 chelating motif and its application in living cell imaging

Abstract

A boron dipyrromethene (BODIPY) derivative (BODTe) with an NTe2 chelating motif exhibits high selectivity for Hg2+ detection. Significant fluorescence enhancement was observed with the chemosensor BODTe in the presence of Hg2+. However, the metal ions Ag+, Al3+, Ca2+, Cd2+, Co2+, Cu2+,Cr3+, Fe2+, Fe3+, Hg2+, Mg2+, Mn2+, Ni2+, Pb2+, and Zn2+ produced only minor changes in the fluorescence values of the system. The association constant (Ka) of Hg2+ binding for the chemosensor BODTe was found to be 3.84×103M−1, with a detection limit of 19.2μM. The maximum fluorescence enhancement caused by Hg2+ binding in the chemosensor BODTe was observed over the pH range of 4.0–10.0. Confocal fluorescence microscopy imaging using RAW 264.7 cells showed that BODTe can be used as an effective fluorescent probe for detecting Hg2+ in living cells.