A turn-on Schiff base fluorescence sensor for zinc ion

A simple Schiff base type fluorescent receptor 1 was prepared and evaluated for its fluorescence response to heavy metal ions. Receptor 1 exhibits an 'off-on-type' mode with high selectivity in the presence of Zn 2+ ion. The selectivity of 1 for Zn 2+ is the consequence of combined effects of chelation-enhanced fluorescence (CHEF), CN isomerization, and inhibition of photoinduced electron transfer (PET).