A dual functional near infrared fluorescent probe based on the bodipy fluorophores for selective detection of copper and aluminum ions

A new near infrared (NIR) fluorescent 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dye with dual functionality was synthesized and characterized. The compound 1 responds to copper ion in NIR region with high selectivity through a photo-induced electron transfer process established between the substituted benzene group in the meso position and the BODIPY core when Cu2+ binds with the four oxygen atoms in the structure, and results in the quenching of the fluorescence. The response range to copper ions was from 10 to 50 μM, and other metal ions including Li+, Na+, K+, Mg2+, Ca2+, Pb2+, Fe3+, Ag+, Hg2+, Co2+, Zn2+, Mn2+, Cd2+, Ni2+ and Al3+ had no interference. When excited at 520 nm, a new emission peak at 568 nm of compound 1 was used to detect Al3+ selectively from 30 μM to 110 μM without any interference from other metal ions including copper ions.