Synthesis of AuPt/graphene quantum dots nanocomposites for determination of glucose by photoluminescence spectroscopy

Abstract

In this study, a novel material, AuPt/graphene quantum dots nanocomposites (AuPt/GQDs NCPs), that have unique optical properties were successfully synthesized. The simple seed-growth method was used to synthesize Au nanoparticles (Au NPs), and these nanoparticles were combined with Pt to form AuPt nanodendrites, which have a unique core–shell structure. In addition, AuPt was distributed over GQDs prepared through a simple “green” approach from an inexpensive natural source of flour. AuPt/GQDs NCPs were analyzed for morphology, properties, and composition by methods, such as UV-vis, FTIR, EDX, and XRD spectroscopies, as well as TEM and SEM. Furthermore, an AuPt/GQDs NCPs substrate was also employed to test glucose detection by photoluminescence (PL) spectroscopy. The results showed that the optical intensity of AuPt/GQDs NCPs is linearly correlated with glucose concentration from 10⁻¹⁰–1 M, with an extremely low limit of detection (LOD ∼10⁻¹⁰ M) with wavelength excitation at 340 nm, showing the promising potential of the synthesized material for glucose detection. Based on these results, the application can be oriented for the detection of pigments and antigens in the diagnosis and early detection of dangerous diseases by means of luminescence spectroscopy.