A new way in nanosensors: Gold nanorods for sensing of Fe(III) ions in aqueous media

A novel and systematic method for sensitive detection of Fe3+ ions in aqueous media using gold nanorods (Au NRs) as nanosensors is presented. One of the most rousing achievements is the detection limit which is found to be 100 ppb for Fe3+ ions. The whole procedure takes not more than 10 min which uses surfactant cetyltrimethylammonium bromide (CTAB) capped seed instead of a citrate to overcome the formation of spherical particles in excess amount along with rods. This work also presents a low cost and effective solution for separation of seed mediated grown Au NRs from co-produced spherical nanoparticles formed in solution. The characterization of nanomaterials and interaction of Fe3+ ions with sensor material was studied by UV-vis spectrophotometer to determine optical properties, while scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to determine morphology. The interaction of Fe3+ ions with Au NRs was investigated by surfaceenhanced Raman scattering (SERS) using crystal violet (CV) molecule. The aspect ratio (length/diameter) of Au NRs was controlled by the amount of surfactant added. The method reported herein is a simple way to detect and determine Fe3+ ions in aqueous solution at the ppb levels and easily applicable for monitoring of Fe3+ ions in water sample. (C) 2013 Elsevier B.V. All rights reserved.