Turn-on fluorescence probe for selective detection of Hg(II) by calixpyrrole hydrazide reduced silver nanoparticle: Application to real water sample

A simple and quick method for the synthesis of water dispersible stable silver nanoparticles has been developed. Calix[4]pyrrole octahydrazide (CPOH), has been successfully used as a reducing as well as stabilizing agent for the synthesis of silver nanoparticles. CPOH-AgNps have been duly characterized by SPR, PSA, TEM and EDX-ray. The ability of CPOH-AgNps as selective and sensitive sensor for various ions (Pb(II), Cd(II), Mn(II), Fe(III), Ni(II), Zn(II), Hg(II), Co(II), Cu(II)) by colorimetry and spectrofluorimetry has been explored. CPOH-AgNps were found to be selective only for Hg(II) ions. Nanomolar concentration of Hg(II) ions can also be determined by spectrofluorimetry by increase in fluorescence intensity. Linear range of detection of Hg(II) ions in water was found to be from 1 nmol/L to 1 μmol/L. The method has been successfully applied for determination of Hg(II) ions in ground water and industrial effluent waste water samples.

Schematic representation showing fluorescence enhancement of CPOH-AgNps in presence of Hg(II) resulting in a turn-on fluorescent assembly.Figure optionsDownload as PowerPoint slide