Polyaniline-Cerium Oxide Nanocomposite for Hydrogen Peroxide Sensor

Hydrogen peroxide (H2O2) sensor has been fabricated by immobilizing horse radish peroxidase (HRP) onto polyaniline(PANI)-cerium oxide (CeO2) nano-composite film onto indium-tin-oxide (ITO) coated glass substrate using electrochemical technique. The HRP/PANI-CeO2/ITO bioelectrode has been characterized using scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy, UV-visible spectroscopy and electrochemical analysis, respectively. This electrode shows improved sensitivity (159.6 nA/mM) and detection limit (50 mM). Further this H2O2 sensor shows high HRP affinity to the PANI-CeO2 matrix as indicated by low value (2.9) mM of Michaelis-Menten constant (K-m). This bioelectrode exhibits maximum response current at pH 7.0 and retains 90% of its initial response current after about 8 weeks.