A sensitive SERS quantitative analysis method for Ni2+ by the dimethylglyoxime reaction regulating a graphene oxide nanoribbon catalytic gold nanoreaction.

Abstract

The nanogold reaction between HAuCl4 and trisodium citrate (TCA) proceeded very slowly at 60°C in a water bath. The as-prepared graphene oxide nanoribbons (GONRs) exhibited strong catalysis during the reaction to form gold nanoparticles (Au NPs) and appeared as a strong surface-enhanced Raman scattering (SERS) peak at 1616cm-1 in the presence of the molecular probe Victoria blue 4R (VB4r). With increase in GONR concentration, the SERS peak increased due to increased formation of Au NPs. Upon addition of dimethylglyoxime (DMG) ligand, which was adsorbed onto the GONR surface to inhibit GONR catalysis, the SERS peak decreased. When Ni2+ was added, a coordination reaction between DMG and Ni2+ took place to form stable complexes of [Ni (DMG)2 ]2+ and the release of free GONR catalyst that resulted in the SERS peak increasing linearly. A SERS quantitative analysis method for Ni2+ was therefore established, with a linear range of 0.07-2.8μM, and a detection limit of 0.036μM Ni2+ .