A Multicomponent Polymer-Metal-Enzyme System as Electrochemical Biosensor for H₂O₂ Detection.

Area of Science:

• Nanomaterials Science
• Electrochemistry
• Biotechnology

Background:

• Development of sensitive and reliable biosensors is crucial for detecting reactive oxygen species like hydrogen peroxide (H₂O₂).
• Existing platforms often face limitations in sensitivity, biocompatibility, or real-time monitoring capabilities.
• Nanocomposite materials offer unique properties for enhanced biosensing applications.

Purpose of the Study:

• To fabricate a novel multicomponent nanohybrid (Au NPs-PDA-PAA-graphene) for biosensing.
• To immobilize Horseradish peroxidase (HRP) onto the nanohybrid for H₂O₂ detection.
• To evaluate the biosensor's performance for H₂O₂ determination and real-time cellular tracking.

Main Methods:

• Surface functionalization of graphene and in-situ growth of gold nanoparticles (Au NPs).
• Fabrication of a multicomponent nanohybrid: Au NPs-polydopamine-poly acrylic acid-graphene (Au NPs-PDA-PAA-graphene).
• Immobilization of Horseradish peroxidase (HRP) and electrochemical characterization.

Main Results:

• The Au NPs-PDA-PAA-graphene nanohybrid demonstrated good hydrophilicity, biocompatibility, and high biomolecule loading capacity.
• The HRP-modified biosensor exhibited high sensitivity for H₂O₂ determination (0.1 μm to 20 mm) with a low limit of detection (0.02 μm).
• The system successfully enabled real-time tracking of H₂O₂ released from macrophage cells.

Conclusions:

• The developed Au NPs-PDA-PAA-graphene nanohybrid serves as an advanced platform for enzyme immobilization and biosensing.
• This biosensor offers a reliable method for both in vitro and in vivo detection of H₂O₂.
• The study highlights the potential of this multicomponent system in bioelectroanalytical chemistry, cellular biology, and pathophysiology.