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 Pb(2+) ion. No enhancement in fluorescent intensity of L was observed on interaction with metal ions - Na(+), K(+), Ca(2+), Cu(2+), Ni(2+), Zn(2+), Cd(2+) and Hg(2+). This signal transduction was found to occur via photoinduced electron transfer (PET) mechanism. A 1:1 complexation between Pb(2+) and L with log β = 7.86 has been proved from fluorescent and UV/Visible spectroscopic data. The detection limit of Pb(2+) was calculated to be 6.3 × 10(-7) M.