An insight into the binding behavior of graphene oxide and noble metal nanoparticles

Abstract

The binding behavior of graphene oxide and metal nanoparticles (Au, Pt, and Pd) was observed by UV–Vis spectroscopy, fluorescence spectroscopy, dynamic light scattering, and zeta potential. Hybrids with a fixed concentration of graphene oxide (GO) were prepared with increasing concentration of metal nanoparticles to observe the effect of binding on their spectroscopic properties, size, and zeta potential. An increase in the absorption spectra of GO after binding with nanoparticles and a gradual decrease in fluorescence emission intensity with increasing concentration of nanoparticles was observed, representing their effective binding. Stern–Volmer plots differentiated the quenching constants of these nanoparticles, where Au shows the lowest and Pd shows the highest quenching among these nanoparticles. The initial hybrids showed more size change as compared to hybrids with a higher concentration of nanoparticles, whereas initial hybrids have charge similar to that of GO and gradual increase in the concentration of nanoparticles bring the charge near to the respective charge of nanoparticles. To the best of our understanding, this is the first report of its kind to study the binding interactions of two different moieties by studying changes occurred in the hydrodynamic radius and zeta potential of hybrids by titration experiments, having applications in surface treatment, drug delivery, and as sensors for environmental pollutants or other classes of organic molecules, etc.