A BINOL-based ratiometric fluorescent sensor for Zn2(+) and in situ generated ensemble for selective recognition of histidine in aqueous solution

A novel BINOL-based ratiometric fluorescent sensor (R2) is presented, which can selectively respond to Zn2+ over Cd2+ and other metal ions with fluorescence enhancement in aqueous solution. The R2 was successfully applied in the imaging of Zn2+ in living cells. Additionally, the in situ generated R2-Zn(II) ensemble could further serve as a probe to distinguish histidine from other amino acids via a displacement mode.