Direct Voltammetry of Copper, Zinc-Superoxide Dismutase Immobilized onto Electrodeposited Nickel Oxide Nanoparticles: Fabrication of Amperometric Superoxide Biosensor
✍ Scribed by Abdollah Salimi ; Abdollah Noorbakhsh; Hossain-Ali Rafiee-Pour; Hedayatollah Ghourchian
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 362 KB
- Volume
- 23
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Abstract
Direct electron transfer of immobilized copper, zinc‐superoxide dismutase (SOD) onto electrodeposited nickel‐oxide (NiOx) nanoparticle modified glassy carbon (GC) electrode displays a well defined redox process with formal potential of −0.03 V in pH 7.4. Cyclic voltammetry was used for deposition of (NiOx) nanoparticles and immobilization of SOD onto GC electrode. The surface coverage (Γ) and heterogeneous electron transfer rate constant (k~s~) of immobilized SOD are 1.75×10^−11^ mol cm^−2^ and 7.5±0.5 s^−1^, respectively. The biosensor shows a fast amperometric response (3 s) toward superoxide at a wide concentration range from 10 µM to 0.25 mM with sensitivity of 13.40 nA µM^−1^ cm^−2^ and 12.40 nA µM^−1^ cm^−2^, detection limit of 2.66 and 3.1 µM based on anodically and cathodically detection. This biosensor exhibits excellent stability, reproducibility and long life time.