Nanoceria based electrochemical sensor for hydrogen peroxide detection.

Area of Science:

• Nanomaterials Science
• Electrochemistry
• Biomedical Sensing

Background:

• Oxidative stress, linked to diseases like cancer and diabetes, involves elevated reactive molecular species such as hydrogen peroxide (H2O2).
• Accurate sensing of H2O2 levels is crucial for disease diagnosis and management.
• Nanoceria exhibits unique redox properties, making it a promising material for free radical scavenging and sensing applications.

Purpose of the Study:

• To synthesize and characterize nanoceria using different capping agents for H2O2 sensing.
• To evaluate the electrocatalytic activity and sensing performance of synthesized nanoceria for H2O2.
• To assess the antioxidant activity of the most effective nanoceria formulation.

Main Methods:

• Synthesis of ceria nanoparticles (Nanoceria) using Hexamethylene-tetra-amine (HMTA) and fructose as capping agents.
• Characterization of Nanoceria particle size, shape, and crystallographic planes using techniques like TEM and XRD.
• Electrochemical sensing of H2O2 using amperometry to determine sensitivity, response time, and limit of detection.
• In vitro antioxidant activity assay using an animal cell line.

Main Results:

• CeO2-HMTA nanoparticles (rhombohedral/cubic, 6.4 nm) and CeO2-fructose nanoparticles (spherical, 5.8 nm) were successfully synthesized.
• CeO2-HMTA exhibited superior electrocatalytic activity towards H2O2 reduction due to better exposure of active crystal planes.
• CeO2-HMTA demonstrated higher sensitivity (21.13 μA cm⁻² mM⁻¹), faster response time (4.8 s), and a lower limit of detection (0.6 μM) compared to CeO2-fructose.
• In vitro studies confirmed the antioxidant activity of CeO2-HMTA.

Conclusions:

• Nanoceria, particularly CeO2-HMTA, is a highly effective material for sensitive and rapid electrochemical detection of hydrogen peroxide.
• The developed sensing platform holds potential for early disease diagnosis and monitoring of oxidative stress.
• CeO2-HMTA shows promise as an antioxidant agent.