Colorimetric Determination of Cu2+ by Glycine-Histidine Dipeptide Functionalized-Gold Nanoparticles

Abstract

This study presents the development of a rapid and straightforward Cu2+ determination method through the interaction of glycine-histidine dipeptides with gold nanoparticles (AuNPs). Here, it was shown that AuNPs were clustered by the attachment of glycine-histidine dipeptides (GH) to the AuNPs. Accordingly, it was obtained from the Uv-vis spectrum that the max of the AuNPs dispersion at 520 nm showed a redshift to a higher energy region. This case was accelerated by adding Cu2+ ions to the medium, indicating an interaction between GH coated-AuNPs and Cu2+ ions, and the particles come together in a shorter time. This finding demonstrates that the developed-analytical method provides more selectivity to Cu2+ when testing in the presence of some other metal ions. The particles and aggregates' sizes were determined by Dynamic Light Scattering (DLS) measurement and Transmission Electron Microscopy (TEM) technique. The determination of Cu2+ in the tap water was also tested by spike using the developed method. In the light of the results obtained, it is thought that the developed analytical method can be quite advantageous for the rapid and selective determination of Cu2+ in water samples.