Effect of processing parameters for electrocatalytic properties of SnO2 thin film matrix for uric acid biosensor

RF sputtered tin oxide (SnO2) thin film matrix has been efficiently exploited for the detection of uric acid. The deposition parameters for SnO2 thin film have been optimized to yield better electrocatalytic properties. A correlation between its electrocatalytic properties with the structural and electrical properties has been made. SnO2 thin film prepared under optimized growth parameter (70% argon in reactive gas ambient of Ar and O-2) exhibits higher mobility of charge carrier and high carrier concentration thereby resulting in enhanced charge transfer characteristics. High surface coverage of uricase onto SnO2 thin films (4.28 x 10(-4) mole cm(-2)), low value of Michaelis-Menten constant (k(m)) 0.18 mM, good linearity in detection of uric acid in the range 0.05-1.00 mM and a fast response of 5 s are attractive features of prepared SnO2 thin film based bioelectrodes for efficient detection of uric acid. The nanoporous and rough surface morphology of SnO2 thin film besides its high carrier mobility in comparison to that of ITO is responsible for the obtained enhanced sensitivity (similar to 700 mu A mM(-1)) and improved sensing response characteristics towards uric acid.