CuO thin film based uric acid biosensor with enhanced response characteristics

An efficient reagentless uric acid biosensor has been realized using a copper oxide (CuO) thin film matrix grown onto platinum (Pt) coated corning glass substrates by pulsed laser deposition (PLD) technique. The p-type CuO matrix successfully introduces redox property in the electrode and provides enhanced electron communication features. Sensing response obtained by the bioelectrocatalytic oxidation of uric acid by uricase/CuO/Pt/glass electrode was studied without any external mediator using cyclic voltammetry (CV) and photometric assay. The studies reveal that the uricase/CuO/Pt/glass bio-electrode exhibits good linearity over a wide range of 0.05 mM to 1.0 mM uric acid concentration with enhanced response of 2.7 mA/mM and high shelf life (>14 weeks). A low Michaelis–Menten constant (Km) of 0.12 mM, indicate that the immobilized enzyme (uricase) has enhanced affinity towards its analyte (uric acid). The results confirm promising application of the p-type CuO thin film matrix for the realization of a reagentless integrated implantable biosensor.

► Article is focused on the development of a reagentless uric acid biosensor. ► Biosensing is based on the bioelectrocatalytic oxidation of uric acid by uricase. ► CuO matrix introduces redox property for charge transfer eliminating need for external mediator. ► Uricase/CuO/Pt/glass bio-electrode shows a fast and good linear response. ► A low Km of 0.12 mM is observed with enhanced sensing response (sensitivity-2.7 mA/mM).