Schiff Base Ligand Coated Gold Nanoparticles for the Chemical Sensing of Fe(III) Ions

Abstract

New Schiff base-coated gold nanoparticles (AuNPs) of type AuNP@L (where L: thiolated Schiff base ligand) have been synthesized and characterized using various spectroscopic techniques. The AuNPs and AuNP@L were imaged by transmission electron microscopy (TEM) and were confirmed to be well-dispersed, uniformly distributed, spherical nanoparticles with an average diameter of 8–10 nm. Their potential applications for chemosensing were investigated in UV-Vis and fluorescence spectroscopic studies. The AuNP@L exhibited selectivity for Fe3+in an ethanol/water mixture (ratio 9 : 1 v/v). The absorption and emission spectral studies revealed a 1 : 1 binding mode for Fe3+, with binding constants of8.5×105and2.9×105 M−1, respectively.