Salicylaldehyde Phenylhydrazone: A New Highly Selective Fluorescent Lead (II) Probe

The fluorescence intensity of salicylaldehyde phenylhydrazone (L), in 1:1 (v/v) CH3OH:H2O was enhanced by ca. 100 times with a blue shift in emission maximum, on interaction with Pb2+ ion. No enhancement in fluorescent intensity of L was observed on interaction with metal ions - Na+, K+, Ca2+, Cu2+, Ni2+, Zn2+, Cd2+ and Hg2+. This signal transduction was found to occur via photoinduced electron transfer (PET) mechanism. A 1:1 complexation between Pb2+ and L with log beta = 7.86 has been proved from fluorescent and UV/Visible spectroscopic data. The detection limit of Pb2+ was calculated to be 6.3 x 10(-7) M.