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 Fe 3+ in an ethanol/water mixture (ratio 9: 1 v/v). The absorption and emission spectral studies revealed a 1: 1 binding mode for Fe 3+, with binding constants of 8.5 × 10 5 and 2.9 × 10 5 M -1, respectively.