Selective Iron (II) colorimetric sensor based on hydroxamic acid-functionalized gold nanoparticles

We have synthesized thiol functionalized gold nanoparticles through ligand exchange reactions. Metal-mediated nanoparticle assembly was studied using mixed monolayer protected gold clusters. Transmission electron microscopy (TEM) was used to determine the nano scale structure of these aggregates. 1H NMR and FT-IR spectroscopy were used to characterize the structure of these nanoparticles. The primary MPNs(monolayer protected nanoparticles) stabilized with alkanethiol were modified to increase the capability of nanoparticles in reaction with metal ligands to form metal complexes. These modified gold nanoparticles are more able to bond with metals such as Iron (II) as the ligand in formation of chemical sensors. The formation of metal complexes was monitored by UV-vis spectroscopy.