rGO based immunosensor amplified using MWCNT and CNF nanocomposite as analytical tool for CA125 detection

Area of Science:

• Electrochemistry
• Materials Science
• Biomedical Engineering

Background:

• Development of sensitive and reliable immunosensors is crucial for early cancer detection.
• Graphene-based nanocomposites offer unique electrochemical properties for biosensing applications.
• CA125 is a significant tumor marker for ovarian cancer, necessitating advanced detection methods.

Purpose of the Study:

• To investigate the electrochemical performance of dual-layer immunosensors utilizing reduced graphene oxide (rGO) and its nanocomposites.
• To evaluate rGO combined with Carbon Nanofibers (CNFs) and Carbon Nanotubes (CNTs) as supporting matrices for CA125 detection.
• To determine the optimal nanocomposite for sensitive and linear quantification of the CA125 antigen.

Main Methods:

• Fabrication of dual-layer immunosensors using rGO, rGO/CNF, and rGO/CNT nanocomposites as transducer materials.
• Electrochemical characterization and performance evaluation based on antibody-antigen immunocomplex formation.
• Analysis of current response decrement correlated with varying CA125 antigen concentrations.

Main Results:

• The rGO/CNF nanocomposite demonstrated excellent linearity (99%) and sensitivity (0.65 μA (μg mL⁻¹)⁻¹) due to enhanced conductivity and surface area.
• The developed immunosensors exhibited a linear working range for CA125 detection from 10 to 32 × 10⁻⁴ μg mL⁻¹.
• A low limit of detection of 0.28 pg mL⁻¹ was achieved, with rGO/CNT also showing improved linearity over rGO alone.

Conclusions:

• Graphene-based nanocomposites, particularly rGO/CNF, significantly improve the performance of dual-layer immunosensors for CA125 detection.
• The enhanced conductivity and surface area of these nanocomposites are key factors for improved sensitivity and linearity.
• These graphene nanocomposite transducer materials hold substantial promise for the clinical detection of oncomarkers.