Polyaniline-cerium oxide nanocomposite for hydrogen peroxide sensor

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Biotechnology

Background:

• Hydrogen peroxide (H2O2) is a crucial biomarker in various biological and environmental processes.
• Development of sensitive and stable H2O2 sensors is essential for accurate monitoring.
• Enzyme immobilization on advanced nanomaterials offers a promising route for enhanced sensor performance.

Purpose of the Study:

• To fabricate and characterize a novel bioelectrode for hydrogen peroxide (H2O2) sensing.
• To investigate the performance of horse radish peroxidase (HRP) immobilized on a polyaniline-cerium oxide (PANI-CeO2) nano-composite film.
• To evaluate the sensitivity, detection limit, affinity, and stability of the developed H2O2 sensor.

Main Methods:

• Electrochemical fabrication of HRP/PANI-CeO2 nano-composite film on an indium-tin-oxide (ITO) coated glass substrate.
• Characterization using scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy, UV-visible spectroscopy, and electrochemical analysis.
• Evaluation of sensor performance including sensitivity, detection limit, Michaelis-Menten constant (K(m)), optimal pH, and long-term stability.

Main Results:

• The HRP/PANI-CeO2/ITO bioelectrode exhibited enhanced sensitivity of 159.6 nA/mM and a detection limit of 50 mM.
• A low Michaelis-Menten constant (K(m)) of 2.9 mM indicated high HRP affinity to the PANI-CeO2 matrix.
• The sensor showed optimal performance at pH 7.0 and maintained 90% of its initial response current for approximately 8 weeks.

Conclusions:

• The developed HRP/PANI-CeO2/ITO bioelectrode demonstrates excellent performance for hydrogen peroxide sensing.
• The PANI-CeO2 nano-composite matrix provides a stable and effective platform for enzyme immobilization, enhancing sensor characteristics.
• This novel bioelectrode holds potential for practical applications in H2O2 detection due to its improved sensitivity, stability, and affinity.