The nanopous Al2O3 material used for the enzyme entrapping in a glucose biosensor

Abstract

This paper presents the enhanced performances of a glucose biosensor constructed with a dielectric multi-layer Si/SiO2/Si 3N4/Al2O3. If the Si/SiO2 system is present in all the silicon integrated sensors, the biosensors processing involves special attention to the intermediate layer responsible for the biological receptors entrapping. A first experience imposes to use the Si3N4 layer over the SiO2 layer mainly to stops the Na+ and K+ ions diffusion from bio-environment toward the silicon transducer. These results are reflected in the CV traced curve and a minimum leakage current. The nitride besides to a nanometric top Al2O 3 layer grown by anodization, helps to a better enzyme entrapping, maintains the GOD active centers and are in agreement with the planar technology requirements. An original Al2O3 deposition technique is presented. The final multilayer structure was characterized as a capacitor by CV-metry, ellipsometry, impedancemetry. © 2010 International Federation for Medical and Biological Engineering.