Amperometric glucose biosensor based on a surface treated nanoporous ZrO2/Chitosan composite film as immobilization matrix

A surface treated nanoporous ZrO2/Chitosan composite matrix was developed to fabricate the glucose biosensor. This material combined the advantages of inorganic nanoparticles, ZrO2, and organic polymer, Chitosan. Glucose oxidase immobilized in the material maintained its activity well as the usage of glutaraldehyde was avoided. The activity of enzyme was 5.02 times greater than the cross-linked enzyme. The interaction between ZrO2/Chitosan and enzyme was characterized with FT-IR spectroscopy. The results of transmission electron microscopy of surface-treated ZrO2/Chitosan film showed that the matrix was porous and highly homogeneous. The parameters affecting the fabrication and experimental conditions of biosensors were optimized. The biosensor had a fast response of less than 10 s. The linear range was 1.25 × 10^-5 to 9.5 × 10^-3 M with a detection limit of 1.0 × 10^-5 M at 3(sigma) and a sensitivity of 0.028 (mu)A mM^-1. The biosensor retained about 75.2% of its original response after one-month storage in a phosphate buffer.