The electrodeposition of Ag nanoparticles on a type I collagen-modified glassy carbon electrode and their applications as a hydrogen peroxide sensor

Silver nanoparticles (Ag NPs) attached to type I collagen-modified glassy carbon (GC) electrodes were successfully synthesized by the electrodepositing method. Atomic force microscopy images showed that many Ag NPs with homogeneous size were formed and uniformly distributed on the type I collagen/GC electrode. The amount, size and distribution of Ag NPs could be controlled by the collagen. The results of electrochemical experiments showed that Ag NPs had an excellent catalytic ability for the reduction of hydrogen peroxide (H2O2), suggesting that they could be used as a sensor to determine H2O2. The good catalytic activity of the Ag NPs was ascribed to the type I collagen that resulted in the homogeneous distribution of Ag NPs with small size. The effects of type I collagen concentration and electrodeposition time on Ag NPs were investigated. When the Ag NPs were used as a sensor to determine H2O2, the sensor could achieve 95% of the steady-state current in less than 2 s and had a linear range of 5.0 mu M to 40.6 mM and a 0.7 mu M detection limit of H2O2 at a signal-to-noise ratio of 3.