CONSTRUCTION OF AN ELECTROCHEMICAL XANTHINE BIOSENSOR BASED ON GRAPHENE/COBALT OXIDE NANOPARTICLES/CHITOSAN COMPOSITE FOR FISH FRESHNESS DETECTION

Authors : Berna Dalkıran, Pınar Esra Erden, Esma Kılıç

Pages : 23-44

Doi:10.18596/jotcsa.54485

View : 11 | Download : 6

Publication Date : 2017-01-09

Article Type : Research Paper

Abstract :Xanthine biosensor based on glassy carbon electrode insert ignore into journalissuearticles values(GC); modified with graphene insert ignore into journalissuearticles values(GR);, Co 3 O 4 nanoparticles and chitosan insert ignore into journalissuearticles values(CH); composite was fabricated. Xanthine oxidase insert ignore into journalissuearticles values(XAO); solution was dropped on the surface of Co 3 O 4 /CH/GR/GC and electrode was placed in saturated glutaraldehyde vapor for the crosslinking of the enzymes. The modified electrode was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimized experimental conditions, xanthine was detected in the concentration range from 5.0×10 -7 to 8.0×10 -5 M with a detection limit of 2.0×10 -7 M. The low Michaelis–Menten constant insert ignore into journalissuearticles values(0.17 mM); suggested enhanced enzyme affinity for the immobilized enzyme as compared to previously reported xanthine biosensors. Moreover, the biosensor exhibited some advantages, such as short response time insert ignore into journalissuearticles values(10 s);, high sensitivity insert ignore into journalissuearticles values(6.58 μA/mM or 74.8 µA/mMcm 2 ); and good reproducibility insert ignore into journalissuearticles values(RSD = 1.2%);. The suitability of the device was verified by xanthine assay in a fish meat. The biosensor provide to be a reliable, easy, fast and economical method for the evaluation of fish freshness.
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