A novel urea biosensor based on zirconia

Electrochemically deposited biocompatible zirconia (ZrO2) film on gold coated glass electrodes has been utilized for the fabrication of urea biosensor. The prepared ZrO2 films and bioelectrodes have been characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and electrochemical techniques, respectively. The urea biosensor, fabricated by immobilizing mixed enzyme [urease (Urs) and glutamate dehydrogenase (GLDH)] on this nanobiomaterial, shows linearity up to 40 mg dL− 1 of analyte (urea) and sensitivity of 0.071 μA/(mM cm− 2) with stability up to 4 months when stored at 4 °C. The low value of Michaelis–Menten constant (Km) estimated using Hans plot as 0.5 mM indicates enhancement in the affinity and/or activity of enzyme attached to this nanostructured biocompatible matrix.