Nonenzymatic biosensor based on Cu(x)O nanoparticles deposited on polypyrrole nanowires for improving detection range.

Cu(x)O (CuO and Cu₂O composite) nanoparticles modified polypyrrole (PPy) nanowires were fabricated and used as a biosensor for detecting glucose (GLC). PPy nanowires were prepared through electrodeposition, while Cu(x)O nanoparticles were deposited on PPy nanowires by electrodeposition and electrochemical oxidation in situ. The scanning electron microscopy images showed the Cu(x)O nanoparticles aligned along the PPy nanowires uniformly and the average size of Cu(x)O nanoparticles is about 90 nm. The electrocatalytic activity of Cu(x)O/PPy/Au towards GLC was investigated under alkaline conditions using cyclic voltammetry and chronoamperometry. The sensor exhibited a linear range up to 8 mM of GLC, which is more than two times of most of the existing non-enzymatic GLC sensors based on CuO or Cu₂O. The sensitivity of the sensor is 232.22 μAmM⁻¹ cm⁻² and detection limit is 6.2 μM (at signal/noise=3). Moreover, the sensor showed excellent selectivity, reproducibility and stability properties. These excellent performances make Cu(x)O/PPy/Au a good nonenzymatic GLC sensor.