Fabrication of Hydrogen Peroxide Biosensors Based on Microelectrode Array of Silicon Dioxide Cavities

A silicon dioxide (SiO2) cavities array was fabricated on indium-tin oxide (ITO) electrode surface with the template of the polystyrene (PS) particles array by using sol-gel technique. The morphology of SiO2 cavities array was highly ordered which was obtained by scanning electrode microscope:. The results of electrochemistrical study showed that the cyclic voltammetric (CV) curve of SiO2 cavities array was in accordance with that of microelectrodes array. Using hemoglobin (Hb) as model protein, an amperometric biosensor for detection of H2O2 was prepared by adsorbing Hb in SiO2 cavities directly. The properties of direct electrochemistry and electrocatalysis of Hb were studied by CV method. The response of the biosensor for H2O2 was fast. A linear relationship between current response and the concentration of H2O2 ranging from 2.03 X 10(-6) to 1.21. X 10(-2) mol/L, was obtained with a detection limit of 5.73 X 10(-7) mol/L. And the apparent Michaelis-Menten constant was 0.266 mmol/L.