A promising biosensing-platform based on bismuth oxide polycrystalline-modified electrode: characterization and its...

Nano-structured bismuth oxide (nano-BiOx) is a suitable material for enzyme immobilization owing to its attractive properties, such as large specific surface area, suitable permeability of the resulting film, the high biocompatibility, and as well as photovoltaic effect from semiconductor nanoparticles. Thus, a new type of amperometric glucose biosensor based on nano-BiOx was constructed. The amperometric detection of glucose was assayed by potentiostating the GOD/nano-BiOx electrode at 0.5 V to oxidize the enzymatically generated hydrogen peroxide. The proposed biosensor provided a linear response to glucose over a concentration range of 1 x 10(-6) M to 1.5 x 10(-3) M with a sensitivity of 51.0+/-0.4 mA/(M cm(2)) and a detection limit of 4 x 10(-7) M based on S/N=3. The apparent Michaelis-Menten constant was calculated to be 2.9 x 10(-3) M. In addition, characterization of nano-BiOx and modified electrode was performed by FT-IR spectroscopy, Raman spectroscopy, scanning electron microscope (SEM) and rotating-disk electrode (RDE) voltammetry.