A new turn-on fluorescent sensor based on NBD for highly selective detection of Hg2+ in aqueous media and imaging in live cells

A new and simple fluorescent probe bearing 7-nitrobenz-2-oxa-1,3-diazole and N, N-bis(thiophen-2- ylmethyl) ethane-1,2-diamine was developed as a fluorescent chemosensor with high selectivity and sensitivity toward Hg2+ over other cations tested. The signaling is due to the coordination of S and N atoms of N, N-bis(thiophen-2-ylmethyl) ethane-1,2-diamine to Hg2+. Upon addition of 30 equivalents of Hg2+, a 45-fold increase in fluorescence emission intensity was observed. Moreover, the probe is further successfully used to image Hg2+ in MCF-7 cells.