title: High-sensitivity amperometric biosensors based on ferrocene-modified linear poly(ethylenimine).
abstract: Amperometric biosensors for glucose and hydrogen peroxide have been built by immobilizing glucose oxidase (GOX) and horseradish peroxidase (HRP) in cross-linked films of ferrocene-modified linear poly(ethylenimine). At pH 7, the glucose sensors generated limiting catalytic current densities of 1.2 mA/cm2. These current densities are approximately 4 times higher than those with other ferrocene-based redox polymers and are comparable to the highest reported values for osmium-based redox polymers with GOX. Because of the high sensitivity of these films (73 nA/cm2.microM), glucose concentrations in the micromolar range could be detected. Similarly, sensors were constructed with HRP-generated current densities of 0.9 mA/cm2 under saturation conditions and sensitivities of 500 nA/cm2.microM. The results show that the ability of Fc-LPEI to effectively communicate with a variety of enzymes has potential applications in measuring low substrate concentrations in implantable biosensors and producing high current outputs in enzymatic biofuel cells.
authors.affiliation: School of Chemical, Biological, and Materials Engineering, Department of Chemistry and Biochemistry, University of Oklahoma Bioengineering Center, University of Oklahoma, Norman, OK 73019, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Merchant
authors.forename: Tu O
authors.initials: TO
authors.lastname: Tran
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Meredith
authors.forename: Tracy C
authors.initials: TC
authors.lastname: Cline
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Glatzhofer
authors.forename: David W
authors.initials: DW
authors.lastname: Schmidtke
mesh_terms: D001388:Aziridines / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation; D002384:Catalysis; D004579:Electron Transport; D005296:Ferrous Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D000075163:Metallocenes; D010084:Oxidation-Reduction
chemical_list: D001388:Aziridines; D005296:Ferrous Compounds; D000075163:Metallocenes; C033132:aziridine; C004998:ferrocene