A remarkable colorimetric probe for fluorescent ratiometric and ON-OFF discriminative detection of Hg2+ and Cu2+ by double-channel imaging in living cells

A novel click-derived monostyryl BODIPY-based fluorescent probe has been prepared. Notably, upon exposure to Hg2+ or Cu2+, it exhibited remarkable blue-shifted absorptions from 592 to either 555 for Hg2+ or 502 nm for Cu2+ with distinct color changes from blue to purple for Hg2+ or yellow for Cu2+ in CH3CN/H2O. Interestingly, its fluorescence showed significant ratiometric (Hg2+) and ON-OFF (Cu2+) changes. Notably, the probe displayed ratiometric fluorescence from 690 to 602 nm with a 65-fold enhancement in fluorescence ratio of I-602/I-690 for Hg2+ and underwent a substantial ON-OFF fluorescence for Cu2+. Furthermore, this probe was successfully used in Hela cells and could easily discriminate Hg2+ and Cu2+ through double-channel imaging. These overall results illustrate that this monostyryl BODIPY potentially serves as a remarkable colorimetric probe for fluorescent ratiometric and ON-OFF discriminative detection of Hg2+ and Cu2+ in solutions and living cells by a remarkable double-channel change.