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Direct Voltammetry of Copper, Zinc‐Superoxide Dismutase Immobilized onto Electrodeposited Nickel Oxide Nanoparticles: Fabrication of Amperometric Superoxide Biosensor
Author(s) -
Salimi Abdollah,
Noorbakhsh Abdollah,
RafieePour HossainAli,
Ghourchian Hedayatollah
Publication year - 2011
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.201000519
Subject(s) - amperometry , cyclic voltammetry , biosensor , chemistry , zinc , copper , detection limit , nuclear chemistry , electron transfer , superoxide dismutase , inorganic chemistry , electrochemistry , electrode , chromatography , photochemistry , organic chemistry , biochemistry , enzyme
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.