Fabrication of Amperometric Urea Sensor Based on Nano-Porous Silicon Technology
Fabrication of Amperometric Urea Sensor Based on Nano-Porous Silicon Technology
- 주제(키워드) Porous silicon , Potentiometric urea sensor , Amperometric urea sensor
- 발행기관 한국물리학회
- 발행년도 2003
- 총서유형 Journal
- UCI G704-000411.2003.42.III.195
- KCI ID ART000990682
- 본문언어 영어
초록/요약
Potentiometric and amperometric urea sensors based on nano-porous silicon (PS) technology are fabricated. Three thin-film electrodes are patterned on p-type silicon wafer by using platinum RF sputtering and Ag evaporation. One of the three electrodes on which urease is immobilized with organic polymeric conductor, the so-called working electrode, is sensitive to urea dissolved in artificially made electrolyte solution. Another electrode is PS-based Ag/AgCl thin-film reference electrode (TFRE). The other is Pt thin-film counter electrode. In a potentiometric urea sensor, urea concentration is related to the measured potential applied between the working and reference electrode according to the Nernst equation. On the other hand, in an amperometric urea sensor, urease-catalyzed hydrolytic reaction of urea causes current flow between the working and counter electrode and the amount of current flow is proportional to the urea concentration, which is based on the Cottrell equation. In this paper, urea sensors are fabricated on p-type silicon wafer by using electrochemical methods in addition to the wafer processing and nano-PS technology. Their electrochemical properties are characterized and result that amperometry is preferable to potentiometry for the detection of urea is obtained.
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