ESIPT-based ratiometric probe for Zn2+ detection based on BINOL framework

A ratiometric BINOL-based fluorescent probe for Zn2+ detection was rationally designed and synthesized. Based on the excited-state intramolecular proton transfer (ESIPT) mechanisms, the probe exhibited a significant variation on emission wavelengths with shifts more than 100nm after combining with Zn2+, with emission colors changing from yellow to blue. Good selectivity and sensitivity of the probe toward Zn2+ could be found in aqueous solution. Sensing mechanism was proposed on the basis of fluorescence, absorption, ESI mass spectrometry, IR spectra, and CD spectra.