title: Fabrication of a carbon fiber paper as the electrode and its application toward developing a sensitive unmediated amperometric biosensor.
abstract: Carbon fiber paper (CFP), a material frequently used as the diffusion layer in fuel cells, was found recently to exhibit a potential as an electrode for the development of sensitive, unmediated biosensors. After nitrogen plasma treatment, the CFP exhibited a quasi-reversible behavior to the redox couple (e.g., ferricyanide) with an electron transfer rate constant of 7.2 × 10(-3)cms(-1). This rate constant is approximately double that of a Pt-electrode and is much higher than that of many carbon-based electrodes. The unmediated CFP-based tyrosinase biosensor fabricated for this study exhibited an optimal working potential and operating pH value of -0.2V and 6.5, respectively. Compared to other unmediated tyrosinase biosensors, the CFP-based tyrosinase biosensor offers a high sensitivity for the monitoring of phenolic compounds (17.8, 7.1, 5.2 and 3.7 μA μM(-1)cm(-2) for catechol, phenol, bisphenol and 3-aminophenol, respectively). The lowest detection limit for catechol, phenol, bisphenol and 3-aminophenol was 2, 5, 5 and 12 nM, respectively. Furthermore, this biosensor exhibited a good repeatability, a fast response time (around 10s), and a wide linear dynamic range of detection for phenolic compounds.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC. cjyuan@mail.nctu.edu.tw
authors.forename: Chiun-Jye
authors.initials: CJ
authors.lastname: Yuan
authors.forename: Chung-Liang
authors.initials: CL
authors.lastname: Wang
authors.forename: Teng Yang
authors.initials: TY
authors.lastname: Wu
authors.forename: Kuo-Chu
authors.initials: KC
authors.lastname: Hwang
authors.forename: Wei-Chi
authors.initials: WC
authors.lastname: Chao
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D002244:Carbon; D000077482:Carbon Fiber; D055664:Electrochemical Techniques; D004800:Enzymes, Immobilized; D004867:Equipment Design; D014442:Monophenol Monooxygenase; D009584:Nitrogen; D010209:Paper; D010636:Phenols / Q000032:analysis; D056951:Photoelectron Spectroscopy
chemical_list: D000077482:Carbon Fiber; D004800:Enzymes, Immobilized; D010636:Phenols; D002244:Carbon; D014442:Monophenol Monooxygenase; D009584:Nitrogen