Nanostructured nickel oxide film for application to fish freshness biosensor

Xanthine oxidase (XOx) has been physisorbed onto nanostructured nickel oxide (n-NiO, similar to 41nm), electrophoretically deposited onto indium-tin-oxide (ITO) glass substrate using poly-ethylene glycol via co-precipitation. The electrochemical response studies of the XOx/n-NiO/ITO bioelectrode show linear response in the xanthine concentration range as 10-200 mu M (R-2 = 0.9989), sensitivity as 0.6214 mu A/mu M cm(2), detection limit as 2.989 mu M, standard deviation as 0.6192 mu A, response time of 15 s with the stability of 100 days. The observed low value (0.0306 mM) Michaelis-Menten constant (K-m) indicates high affinity of XOx towards xanthine. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4736578]