Fluorimetric detection of Sn2 + ion in aqueous medium using Salicylaldehyde based nanoparticles and application to natural samples analysis

Abstract

The fluorescent 2-[(E)-(2-phenylhydrazinylidene)methyl]phenol nanoparticles (PHPNPs) were prepared by a simple reprecipitation method. The prepared PHPNPs examined by Dynamic Light Scattering show narrower particle size distribution having an average particle size of 93.3nm. The Scanning Electron Microphotograph shows distinct spherical shaped morphology of nanoparticles. The blue shift in UV-absorption and fluorescence spectra of PHPNPs with respect to corresponding spectra of PHP in acetone solution indicates H- aggregates and Aggregation Induced Enhanced Emission (AIEE) for nanoparticles. The nanoparticles show selective tendency towards the recognition of Sn2+ ions by enhancing the fluorescence intensity preference to Cu2+, Fe3+, Fe2+, Ni2+, NH4+, Ca2+, Pb2+, Hg2+ and Zn2+ ions, which actually seem to quench the fluorescence of nanoparticles. The studies on Langmuir adsorption plot, fluorescence lifetime of PHPNPs, DLS-Zeta sizer, UV–visible and fluorescence titration with and without Sn2+ helped to propose a suitable mechanism of fluorescence enhancement of nanoparticles by Sn2+ and their binding ability during complexation. The fluorescence enhancement effect of PHPNPs induced by Sn2+ is further used to develop an analytical method for detection of Sn2+ from aqueous medium in environmental samples.