A highly selective fluorescent probe for cadmium ions in aqueous solution and living cells.

An organic salt based on double 1,3,4-oxadiazole derivatives as fluorophores and BAPTA as a receptor has been designed for detection of Cd(2+). The fluorescent probe exhibits high selectivity for Cd(2+) and a low detection limit of 20 nM in aqueous solution, making it useful for Cd(2+) imaging in living MCF-7 cells.