Pt-Au nanocorals, Pt nanofibers and Au microparticles prepared by electrospinning and calcination for nonenzymatic glucose sensing in neutral and alkaline environment

Pt-Au nanocorals, Pt nanofibers and Au microparticles have been successfully fabricated following a similar facile electrospinning-calcination two-step synthetic route. Scanning and transmission electron microscopies were employed to characterize the morphologies of the as-prepared samples, while X-ray diffraction was performed to investigate the structures and compositions. The Pt-Au nanocorals, Pt nanofibers and Au microparticles were employed for nonenzymatic glucose detection in neutral buffer as well as in alkaline media. Compared with Pt nanofibers and Au microparticles, a strong synergistic effect between Pt and Au in Pt-Au nanocorals was observed, leading to enhanced electrocatalytic activity towards glucose oxidation in neutral and alkaline environments. Specifically, insignificant glucose oxidation was observed at gold microparticles modified electrode in both electrolytes, while a higher sensitivity, lower detection limit and a wider liner range in both neutral and alkaline electrolytes are obtained at Pt-Au nanocorals modified electrode than those at Pt nanofibers modified electrode. In alkaline solution, Pt-Au nanocorals showed high sensitivity (24.6 mu A mM(-1) cm(-2)) and lower detection (3.2 mu m) with a linear range up to 7.2 mM; while in neutral media, Pt-Au nanocorals exhibited a wider liner range up to 22 mM with a sensitivity of 2.1 mu A mM(-1) cm(-2) and detection limit of 28 mu M. Although both Pt-Au nanocorals and Pt nanofibers suffer from significant interference from ascorbic acid and uric acid at physiological concentration when operated in neutral electrolyte, such interference on Pt-Au nanocorals could be effectively suppressed in alkaline electrolyte while server interference was still observed on Pt nanofibers. These results suggest that the as-prepared Pt-Au nanocoral is a promising nanomaterial for design and fabrication of electrochemical devices for glucose detection. (C) 2012 Elsevier B.V. All rights reserved.