The use of single walled carbon nanotubes dispersed in a chitosan matrix for preparation of a galactose biosensor
- 作者：Jan Tkac ; James W. Whittaker ; Tautgirdas Ruzgas
- 关键词：Carbon nanotube ; Nafion ; Chitosan ; Galactose oxidase ; Interferents ; Blood plasma
- 刊名：Biosensors and Bioelectronics
- 出版年：2007
- 期刊代码：12_09565663
- 类别：ch
- 出版时间：15 March 2007
- 卷：22
- 期：8
- 页码：1820-1824
- 文件大小：278 K
摘要
Chitosan was chosen as a natural polymer for dispersion of single walled carbon nanotubes (SWNT) based on its ability to efficiently solubilize SWNTs to form a stable dispersion. Moreover, chitosan films deposited on a surface of a glassy carbon (GC) electrode are mechanically stable. Further stabilisation of the chitosan film containing SWNT (CHIT–SWNT) was done by chemical crosslinking with glutaraldehyde and free aldehyde groups produced a substrate used for covalent immobilisation of galactose oxidase (GalOD). Different galactose biosensor configurations were tested with optimisation of composition of inner and outer membrane; and enzyme immobilisation procedure, as well. Detection of oxygen uptake by GalOD on CHIT–SWNT layer at −400 mV is robust and, when flow injection analysis (FIA) was applied for assays, a low detection limit (25 μM) and very high assay throughput rate (150 h−1) was achieved. This new galactose biosensor offers highly reliable detection of galactose with R.S.D. well below 2%and it has been successfully applied to assaying galactose in a blood sample with recovery index between 101.2 and 102.7%.