ABSTRACTUric acid biosensor has been developed using tin oxide (SnO2) thin film. The electrochemistry of the developed thin film based electrode is investigated by using cyclic voltammetry. The obtained results demonstrate that the semiconducting SnO2 matrix offers a striking electrocatalytic activity to the immobilized uricase towards the oxidation of uric acid and promotes the transfer of electrons from the active sites of enzyme onto the electrode. SnO2 thin film matrix gives a high sensitivity of 0.2 mA/mM and a shelf life of 20 weeks. Moreover, SnO2 electrode exhibits excellent selectivity and outstanding analytical stability and reproducibility, which enables a reliable and selective determination of uric acid. The SnO2 based uric acid biosensor shows a linear variation in a wide range from 0 to 1.0 mM of uric acid concentration and the Michaelis Menten Constant (Km) is estimated to be 0.28 mM which indicated the high affinity of uricase towards its analyte (uric acid). The results indicate that the SnO2 thin film matrix offers a new and promising platform for the development of novel biosensors.
