Fabrication and characterization of glucose sensors based on a microarray H2O2 electrode

A glucose sensor was recently developed by modifying an immobilized GOD (glucose oxidase) membrane and coating Nafion diffusion limiting membrane over an amperometric H2O2 MAE (microarray electrode), which was fabricated by using standard planar processing. The chip of the sensor is 2.5 mm by 15. The MAE is composed of an Ag/AgCl RE (reference electrode), a Pt CE (counter electrode) and two sets of Pt WE (working electrode), each set consists of five bands. Silicon nitride was chosen as the top insulator. Six MAEs different in both width and length of the band were examined and the MAE with the narrowest width (10 microns) of bands exhibits the best electrochemical performances. The glucose sensor based on the MAE B1-2 presents a linear range of 0.5-40 mM glucose at 37 degrees C with a 1/15 M phosphate buffer solution (pH = 7.0) as supporting electrolyte. The sensitivity, background current, response time, CV (coefficient of variation) and long-term stability of the sensor are 7.1 +/- 0.5 nA/mM, 2 +/- 0.5 nA, 30 s, 3.4% and 6 days respectively.