Optical Studies of Graphene Oxide/Poly(amidoamine) Dendrimer Composite Thin Film and Its Potential for Sensing Hg2+ Using Surface Plasmon Resonance Spectroscopy

In this study, a graphene oxide/poly(amidoamine) (GO/PAMAM) dendrimer composite thin film was developed for the potential detection of Hg2+ using surface plasmon resonance (SPR) spectroscopy. Fourier transform infrared spectroscopy (FTIR) analysis proved the presence of amino, carboxylic acid, carboxyl, and hydroxyl groups in the GO/PAMAM thin film. The optical properties of the thin film were characterized using UV-Vis absorption spectroscopy. The UV-Vis analysis showed that the absorption of the GO/PAMAM thin film was high with an optical band gap of 4.01 eV. The incorporation of the GO/PAMAM thin film with SPR spectroscopy produced positive responses towards various Hg2+ concentrations. Atomic force microscopy results indicated that the thin film has an irregular edge and hence proved the interaction of mercury ions with the thin film.