title: Incorporation of single-walled carbon nanotubes into ferrocene-modified linear polyethylenimine redox polymer films.
abstract: In this study, we describe the effects of incorporating single-walled carbon nanotubes (SWNTs) into redox polymer-enzyme hydrogels. The hydrogels were constructed by combining the enzyme glucose oxidase with a redox polymer (Fc-C(6)-LPEI) in which ferrocene was attached to linear poly(ethylenimine) by a six-carbon spacer. Incorporation of SWNTs into these films changed their morphology and resulted in a significant increase in the enzymatic response at saturating glucose concentrations (3 mA/cm(2)) as compared to films without SWNTs (0.6 mA/cm(2)). Likewise, the sensitivity at 5 mM glucose was significantly increased in the presence of SWNTs (74 μA/cm(2)·mM) as compared to control films (26 μA/cm(2)·mM). We demonstrate that the increase in the electrochemical and enzymatic response of these films depends on the amount of SWNTs incorporated and the method of SWNT incorporation. Furthermore, we report that the presence of SWNTs in thick films allows for more of the ferrocene redox centers to become accessible. The high current densities of the hydrogels should allow for the construction of miniature biosensors and enzymatic biofuel cells.
authors.affiliation: Carbon Nanotube Technology Center, University of Oklahoma, 100 East Boyd, Norman, Oklahoma 73019, United States.
authors.forename: Tu O
authors.initials: TO
authors.lastname: Tran
authors.forename: Emily G
authors.initials: EG
authors.lastname: Lammert
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Merchant
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Brunski
authors.forename: Joel C
authors.initials: JC
authors.lastname: Keay
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Johnson
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Glatzhofer
authors.forename: David W
authors.initials: DW
authors.lastname: Schmidtke
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D004563:Electrochemistry; D004579:Electron Transport; D005296:Ferrous Compounds / Q000737:chemistry*; D005949:Glucose Oxidase / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry; D000075163:Metallocenes; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005296:Ferrous Compounds; D020100:Hydrogels; D000075163:Metallocenes; D037742:Nanotubes, Carbon; D011094:Polyethyleneimine; D005949:Glucose Oxidase; C004998:ferrocene