Novel synthesis of AuPt bimetallic nanocubes combined with graphene quantum dots for non-enzymatic sensor of glucose determination by electrochemical method

Abstract

In this study, AuPt bimetallic nanocubes (AuPt NCBs) were successfully combined with graphene quantum dots (GQDs) by a simple and easy-to-implement method at 80oC for 90 min. In particular, graphene quantum dots (GQDs) nanoparticles were synthesized by hydrothermal method at 190oC for 8 h, using raw materials from wheat flour, which are environmentally friendly materials, available and abundant in nature. AuPt bimetallic nanocubes were obtained from the synthesis of Au nanocubes (Au NCBs), followed by AuPt nanoparticles obtained when reacted at 140oC for 2 h by hydrothermal method to form AuPt core/shell nanocubes (AuPt NCBs). Besides, the synthesized AuPt NCBs/GQDs nanocomposites were also characterized, shape, size and composition by: UV-vis, FTIR, XRD, TEM, EDX, XPS, and AFM. The obtained results show that the Au nanocubes (Au NCBs) have an average particle size of ~ 39 nm; the size of AuPt NCBs and GQDs nanoparticles are ~ 40–44 nm and ~ 3–5 nm in size, respectively. Furthermore, AuPt NCBs/GQDs nanocomposites are also used as non-enzymatic catalysts for the oxidation/reduction of glucose by cyclic voltammetry (CV). The obtained results indicate that the AuPt NCBs/GQDs nanocomposites with high catalytic activity are capable of detecting glucose in a wide concentration range from 10− 12 M to 1 M, with an extremely low limit of detection (LOD) of concentration glucose levels (~ 10− 12 M). Therefore, AuPt NCBs/GQDs are novel and promising nano-catalysts that can be applied as catalysts with high activity oriented to many fields such as environmental treatment, fuel energy cells, or sensors to make bio-chip devices for early diagnosis of serious diseases such as diabetes, gout or cancer, etc., in present and the future.