Dual-channel fluorescent probe based on bisphenol A-rhodamine for Zn2+ and Hg2+ through different signaling mechanisms and its bioimaging studies

A novel dual channel probe based on bisphenol A-rhodamine (BAR) was successfully designed and synthesized with high selectivity and sensitivity to Zn2+ and Hg2+ ions. BAR exhibited an effectively selective and sensitive recognition toward Zn2+ and Hg2+ ions through two different mechanisms (i.e. ESIPT and FRET) in pure MeCN and MeCN-H2O (v/v = 8/2, 5 mM, HEPES, pH 7.0) over other cations. The complexation properties of BAR with Zn2+ and Hg2+ ions were examined by 1H NMR, 13C NMR and FTIR experiments. The detection limits for Zn2+ and Hg2+ were 2.21 and 2.16 μM, respectively. Furthermore, possible utilization of BAR as bio-imaging fluorescent probe to detect Hg2+ in human prostate cancer cell lines was also observed by Fluorescent Cell Imager.