Amperometric Biosensors Based on Redox Polymer-Carbon Nanotube-Enzyme Composites

摘要

Based on their size and unique electrical properties, carbon nanotubes offer the exciting possibility of developing ultrasensitive, electrochemical biosensors. In this study, we describe the construction of amperometric biosensors based on the incorporation of single-walled carbon nanotubes modified with enzyme into redox polymer hydrogels. The composite films were constructed by first incubating an enzyme in a single-walled carbon nanotube (SWNTs) solution and then cross-linking within a poly [(vinylpyridine)Os(bipyridy)_2CI~(2+/3+)] polymer film. Incorporation of SWNTs, modified with glucese oxidase, into the redox polymer films resulted in a 2-10-fold increase in the oxidation and reduction peak currents during cyclic voltammetry, while the glucose electrooxidation current was increased 3-fold to approx1 mA/cm~2 for glucose sensors. Similar effects were also observed when SWNTs wese modified with horseradish perxidase prior to incorporation into redox hydrogels.