Simple terpyridine based Cu(II)/Zn(II) complexes for the selective fluorescent detection of H2S in aqueous medium

Simple 4′-phenyl-2,2′:6′,2″-terpyridine derived metal complexes (1.Cu and 1.Zn) are studied for selective detection of H2S, based on metal displacement approach. Probe 1.Cu exhibits turn-on and 1.Zn exhibits turn-off fluorescence detection of H2S both in aqueous buffer and biological medium. In the presence of H2S, fluorescent output signal turned ON or OFF by simply changing the metal from copper to zinc in terpyridine coordination center. The advantages of the probes include a low detection limit (2.2 μM for 1.Cu and 31 μM for 1.Zn), fluorescent response, good selectivity, high sensitivity and fast response (45-60 s) and easy to synthesize the probe. Furthermore, the detection of H2S could be used for the construction of INHIBIT and NAND molecular logic gates based on the optical signal.