Functionalized vertically aligned carbon nanofibers as scaffolds for immobilization and electrochemical detection of redox-active proteins

TitleFunctionalized vertically aligned carbon nanofibers as scaffolds for immobilization and electrochemical detection of redox-active proteins
Publication TypeJournal Article
Year of Publication2006
AuthorsBaker, SE, Colavita, PE, Tse, KY, Hamers, RJ
JournalChemistry of Materials
Volume18
Pagination4415-4422
Date PublishedSep
Type of ArticleArticle
ISBN Number0897-4756
Accession NumberISI:000240072000032
Keywordsvoltammetry
Abstract

We have investigated the functionalization of vertically aligned carbon nanofibers with the redox-active protein cytochrome c and have characterized the resulting chemical and electrochemical activity. A comparison of monolayers with different terminal groups shows that those exposing carboxylic acid groups are most effective at binding active cytochrome c to carbon nanofibers. Cyclic voltammetry (CV) measurements reveal redox peaks due to electrochemical activity of the nanofiber-bound protein. CV and chemical measurements of enzymatic activity both show that nanofibers modified with cytochrome c yield approximately 10 times more activity than similarly modified surfaces of glassy carbon and gold. However, cytochrome c-modified nanofibers yield a high capacitive background, reducing the signal-to-noise ratio of the electrical measurements. We attribute this in part to inhomogeneous functionalization of the nanofibers at edge-plane versus basal-plane sites on the nanofiber surface, leading to leaky monolayers that yield increased capacitance. Our results demonstrate the ability to link chemically and electrochemically active proteins to nanofibers in a manner that preserves their activity and provide insight into the nanometer-scale factors that control the resulting chemical and electrochemical properties of biologically modified nanostructured electrodes.

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