Highly stable amplified low-potential electrocatalytic detection of NAD⁺at azure-chitosan modified carbon electrodes

• Main Authors: Tanin Tangkuaram, Joseph Wang, Marcela C. Rodríguez, Rawiwan Laocharoensuk, Waret Veerasai
• Other Authors: Arizona State University
• Format: Article
• Published: 2018
• Subjects: Engineering; Materials Science; Physics and Astronomy
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/24452
• Institution: Mahidol University

The incorporation of chitosan (CHIT) into an Azure-C (AZU) film, covering a glassy carbon electrode, greatly facilitates the electroreduction of NAD+to allow a highly stable low-potential amplified cathodic detection of this enzymatic cofactor. Higher and sharper NAD+reduction peaks are thus observed at lower potentials at the AZU/CHIT coated electrode, compared to those observed at the AZU-modified electrode. Such formation of an AZU/CHIT surface layer leads also to a highly stable NAD+response. For example, 98% of the initial amperometric response of NAD+at the AZU/CHIT coated electrode is retained after 20 min stirring 6 × 10-3M NAD+solution (compared to 69% at the AZU-modified electrode). Factors affecting the enhanced electrocatalytic response, including the composition of the AZU/CHIT layer or pH, are examined. Electrochemical parameters for the NAD+reduction, including the α, k or E0′, are estimated by cyclic voltammetry. The improved NAD+detection of NAD+reflects the improved film formation imparted by the CHIT component. The new modified electrode could find a wide range of biotechnological applications, including biosensors, bioreactors and biofuel cells. © 2006 Elsevier B.V. All rights reserved.