An amperometric on-chip glucose biosensor based on enzyme entrapment with pre-reaction to lower interference in a flow injection system
P.-C. Nien, M.-C. Huang, F.-Y. Chang and K.-C. Ho
National Taiwan University, TW
glucose biosensor, on-chip, interference, microsystem
In this study, the flow injection analysis was applied to the enzyme-entrapped sensor on a chip for sensing glucose. The microelectrode arrays on a chip of 7×3.5 cm2 were fabricated by standard photolithographic and the microfluidic channel height of 100 micrometer was formed by combining the cover of poly(dimethylsiloxane). The conducting polymer, poly(3,4-ethylenedioxythiophene), was electropolymerized with glucose oxidase at a flow rate of 5 ml/hr on “WE1”. While in the background buffer, the enzyme electrode was applied a potential of 0.7 V (vs. Ag) by injecting different concentrations of glucose (Glu) sample for sensing H2O2. The linear regression from 0.1 mM to 20 mM with a sensitivity of 8 nA mm-2 mM-1. Besides, the response time (t95) and the recovery time are about 30 s and 230 s, respectively. The pre-reaction section, “WE2”, was applied at 0.7 V (vs. Ag) to electrocatalyze the oxidized-favor materials of the injecting samples. For the single-potential, the 0.08 mM AA and blend 0.08 mM AA and 10 mM Glu samples reached 31.3 % and 145.5 % of the sensing current of 10 mM Glu, respectively. In contrast, the sensing current of blend sample reached 99.6 % of 10 mM Glu in the bi-potential test.
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Nanotech 2007 Conference Program Abstract