New method for the detection of enzyme immobilized on Si-based glucose Biosensors

Glucose oxidase molecular layers immobilized on planar and porous SiO2 substrates were characterized with techniques commonly used in microelectronics technology. Both planar and porous SiO2 were used as inorganic platforms for the enzyme bonding. The immobilization protocol on planar SiO2 was characterized using contact angle, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), while energy dispersive X-ray analysis (EDX) coupled with scanning electron microscopy (SEM) were used on porous SiO2 samples. A conclusive confirmation of the enzyme presence in the SiO2 matrix was obtained by gold nano particles labeling. This last measurement technique could be implemented to determine the enzyme concentration in the porous SiO2 layer.