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Amperometric Ethanol Biosensor Based on Carbon Nanotubes Dispersed in Sol–Gel‐Derived Titania–Nafion Composite Film
Author(s) -
Choi Han Nim,
Lyu YoungKu,
Han Jee Hoon,
Lee WonYong
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200703886
Subject(s) - biosensor , nafion , amperometry , materials science , composite number , carbon nanotube , chemical engineering , sol gel , electrode , nanotechnology , electrochemistry , composite material , chemistry , engineering
Composite solution of sol–gel‐derived titania and perfluorosulfonated ionomer (Nafion) was used as a solubilizing agent for multiwalled carbon nanotubes (CNT) as well as an encapsulation matrix for alcohol dehydrogenase (ADH) for the fabrication of a highly sensitive and stable amperometric ethanol biosensor. ADH was immobilized within a thin film of CNT–titania–Nafion composite film coated on a glassy carbon electrode. Because of the mesoporous nature of the CNT–titania–Nafion composite film, the present biosensor exhibited remarkably fast response time within 2 s. The presence of CNT in the composite film increases not only the sensitivity of the ethanol biosensor but also the long‐term stability of the biosensor. The present biosensor responds linearly to ethanol in the wide concentration ranges from 1.0×10 −5 M to 3.0×10 −3 M with the sensitivity of 51.6 mA M −1 cm −2 . The present biosensor showed good long‐term stability with 75% of its activity retained after 4 weeks of storage in 50 mM phosphate buffer at pH 7.0.