Electrochemical Sensing Based on Redox Mediation at Carbon Nanotubes
Autor: | Waldemar Gorski, Maogen Zhang |
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Rok vydání: | 2005 |
Předmět: | |
Zdroj: | Analytical Chemistry. 77:3960-3965 |
ISSN: | 1520-6882 0003-2700 |
DOI: | 10.1021/ac050059u |
Popis: | An electrochemical sensing platform was developed based on the integration of redox mediators and carbon nanotubes (CNT) in a polymeric matrix. To demonstrate the concept, a redox mediator Azure dye (AZU) was covalently attached to polysaccharide chains of chitosan (CHIT) and interspersed with CNT to form composite films for the amperometric determination of beta-nicotinamide adenine dinucleotide (NADH). The incorporation of CNT into CHIT-AZU matrix facilitated the AZU-mediated electrooxidation of NADH. In particular, CNT decreased the overpotential for the mediated process by an extra 0.30 V and amplified the NADH current by approximately 35 times (at -0.10 V) while reducing the response time from approximately 70 s for CHIT-AZU to approximately 5 s for CHIT-AZU/CNT films. These effects were discussed in terms of the AZU/CNT synergy, which improved charge propagation through the CHIT-AZU/CNT matrix. The concept of CNT-facilitated redox mediation in polymeric matrixes has a potential to be of general interest for expediting redox processes in electrochemical devices such as sensors, biosensors, and biological fuel cells and reactors. |
Databáze: | OpenAIRE |
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