Glucose biosensor based on the highly efficient immobilization of glucose oxidase on Prussian blue-gold nanocomposite films

A glucose biosensor was developed, which was based on Prussian blue-gold (PB-Au) nanocomposite films and platinum nanoclusters (Pt-NCs). Prussian blue (PB), as an electron mediator, was electrochemically deposited on the glass carbon electrode (GCE) in the presence of chloroauric acid, forming PB-Au nanocomposite films. Then, Pt-NCs were electrodeposited to construct a bilayer film. At last, glucose oxidase was modified on the electrode with the bilayer film and the film of Nafion (Nf) was used to prevent the glucose oxidase (GOD) from leaking off. The resulting amperometric glucose biosensor exhibited a fast response time (within 8 s) and a linear calibration range from 3.0 μM to 1.1 mM with a low detection limit of 1.0 μM glucose (S/N = 3). With the low operating potential, the biosensor showed little interference to the possible interferents, including acetum acid, uric acid and arginine, indicating an excellent selectivity. The improved performances of resulting electrode for electrocatalysis-oxidation glucose were ascribed to the high surface-to-volume ratio and the excellent catalytic activity of nanoparticles. The combination of the PB-Au nanocomposite and Pt-NCs would open new horizons for fabrication of biosensors and biocatalysts.