A microfabricated glucose biosensor based on an amperometeric hydrogen
peroxide electrode has been developed. A sol-gel layer with 5 Angstro
m pore size and 2 mu m thickness was used as the glucose oxidase entra
pping matrix. The sol-gel matrix formed over the silicon-based sensor
has good mechanical and chemical stability, and the ability to entrap
a large amount of enzyme. The miniaturized electrode sensing system is
composed of platinum as both working and counter electrodes and silve
r as a reference electrode. Nafion(R) coating was applied as the inter
ference limiting layer. A series of technologies, such as standard pho
tolithography, electron beam evaporation and image reverse lift-off we
re utilized for mass production allowing 143 electrodes to be produced
at the same time. The effect of oxidable interferences was < 10% of t
he background value of the sensor response. Calibration tests of a ser
ies of individual sensors manufactured from the same silicon wafer and
dip coated in the same conditions, showed a highly reproducible respo
nse characteristics (linear range up to 500 mg dl(-1) and mean sensiti
vity of 0.54 +/- 0.14 nA mg(-1) dl(-1) (n = 10)). (C) 1998 Elsevier Sc
ience B.V. All rights reserved.