An enzymatic biosensor for hydrogen peroxide based on CeO2 nanostructure electrodeposited on ITO surface

Area of Science:

• Electrochemistry
• Biosensors
• Nanomaterials

Background:

• Enzymatic biosensors are crucial for detecting various analytes.
• Direct electrochemistry of enzymes offers a mediator-less detection approach.
• Nanostructured materials enhance biosensor performance due to their large surface area.

Purpose of the Study:

• To develop an amperometric enzymatic biosensor for hydrogen peroxide (H2O2) detection.
• To utilize the direct electrochemistry of myoglobin (Mb) immobilized on porous cerium dioxide (CeO2) nanostructures.
• To investigate the electrochemical properties and performance of the fabricated biosensor.

Main Methods:

• Electrodeposition of porous CeO2 nanostructured film on an indium tin oxide (ITO) substrate.
• Immobilization of myoglobin (Mb) on the CeO2/ITO surface.
• Electrochemical characterization using cyclic voltammetry (CV) and differential pulse voltammetry (DPV).
• Amperometric detection of H2O2.

Main Results:

• The CeO2 film exhibited a large specific surface area and unique nanostructure.
• Mb immobilized on CeO2/ITO showed facile, direct electrochemistry with a surface-controlled, one-electron transfer process.
• The biosensor demonstrated high sensitivity (detecting H2O2 as low as 0.6μM) and stability.
• A rapid response time of ~8s was achieved for H2O2 detection up to 3mM.

Conclusions:

• Porous CeO2 nanostructured films are effective platforms for immobilizing enzymes.
• The developed Mb/CeO2/ITO biosensor is a promising reagent-less system for sensitive and stable H2O2 detection.
• CeO2 is a viable candidate material for fabricating advanced enzymatic sensors.