Renewable Protein A modified graphite-epoxy composite for electrochemical immunosensing

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Protein A facilitates antibody binding to the Fc region, enabling antibody immobilization.
• Developing renewable transducers is crucial for improving the longevity and reusability of immunosensors.
• Existing immunosensing methods often lack efficient antibody immobilization and surface renewal capabilities.

Purpose of the Study:

• To report a novel rigid and renewable transducing material for electrochemical immunosensing.
• To investigate the use of Protein A bulk-modified graphite-epoxy biocomposite (ProtA-GEB) as an affinity matrix for antibody immobilization.
• To evaluate the performance and stability of the ProtA-GEB transducer in a model competitive immunoassay.

Main Methods:

• Fabrication of Protein A bulk-modified graphite-epoxy biocomposite (ProtA-GEB) transducers.
• Comparison of ProtA-GEB with surface-modified transducers (ProtA/GEC and IgG/GEC).
• Electrochemical and microscopic characterization of the transducer material.
• Optimization of immunosensor design and stability assessment.
• Application in a model competitive immunoassay using enzymatic labeling and amperometric detection.

Main Results:

• The ProtA-GEB demonstrated a renewable electrode surface through a simple polishing procedure.
• The biocomposite material served as both a transducer and a reservoir for Protein A.
• Performance evaluation in a model competitive immunoassay showed the efficacy of the ProtA-GEB transducer.
• Electrochemical and microscopic characterization confirmed the material's properties and stability.

Conclusions:

• The developed ProtA-GEB offers a promising, rigid, and renewable material for electrochemical immunosensing.
• The novel approach provides a significant advantage over classical immunoassays due to its reusability.
• This biocomposite material represents a valuable advancement in the field of immunosensor technology.