Diameter effect of electrospun carbon fiber support for the catalysis of Pt nanoparticles in glucose oxidation

Electrospun carbon fibers (CFs) with diameters of 39nm (CF_39nm), 158nm (CF_158nm), and 309nm (CF_309nm) were used as Pt-catalyst supports for a glucose oxidation reaction. Based on experimentally balanced comparisons using electrochemical methods, CF_39nm with higher curvature and smaller diameter had a greater number of Pt atoms on the surface. Compared with the CF_158nm and CF_309nm systems, CF_39nm has a higher electrochemically real surface area and greater catalytic activity on glucose oxidation. The Tafel analyses demonstrated that the exchange current density from an early rest potential (-0.81V) for the CF_39nm system was 9.08×10^-3mAcm^-2, greater than 8.41×10^-3mAcm^-2 for CF_158nm-supported Pt nanoparticles and 7.39×10^-3mAcm^-2 for CF_309nm-supported Pt nanoparticles. In addition, as data supporting the catalytic characterization for glucose oxidation, all of the CF-supported Pt nanoparticles showed remarkable tolerance to foreign substances in the application of a non-enzymatic glucose sensor, where CF_39nm-supported Pt nanoparticles (Pt/CF_39nm) showed a higher sensitivity (2.03μAmM^-1cm^-2), detection limit (33μM), and linear range (0.3-17mM). The high recovery by serum sample analyses further confirmed the potential of Pt/CF_39nm as a glucose sensor. The promising results showed the feasibility of these electrospun CFs being applied for both glucose fuel cells and non-enzymatic glucose sensors.