Document Type : Article
Catalysis and Nanostructured Laboratory, School of Chemical Engineering, University of Tehran, Tehran, Iran
Nanoelectronics Centre of Excellence, University of Tehran, Tehran, P.O. Box 11365-4563, Iran.
Department of Chemical Engineering, Hamedan University of Technology, Hamedan, 65155, Iran
Multi-walled carbon nanotubes (MWCNTs) were functionalized using a dielectric barrier discharge plasma in presence of H2O-saturated air at 70˚C and atmospheric pressure. The functionalized MWCNTs (F-CNTs) were decorated with electrochemically deposited 10 nm NiO nanoparticles, followed by immobilization of glucose oxidase (GOx) and the modified electrode was utilized for electrochemical detection of glucose. TEM, FE-SEM, TPD and XPS techniques were used to characterize the NiO/F-CNTs samples. The maximum amount of oxygenated functional groups such as carbonyl, hydroxyl and carboxylic groups was formed at the plasma exposure time of 4 min. The optimum chronoamperometric deposition time of NiO was 3 min.
The presence of GOx on the NiO/F-CNTs electrode displayed a quasi-reversible and surface-controlled redox wave around −0.52 V with a peak to peak separation of 0.05 V. The GOx/NiO/F-CNTs electrode showed a linear performance in the range of 0.2-3.8 mM glucose with detection limit of 93.0 µM and sensitivity of 2.16 µA.mM−1.