Ionic liquid functionalized graphene/Au nanocomposites and its application for electrochemical immunosensor.

Area of Science:

• Nanomaterials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Developing sensitive and reliable biosensors is crucial for early disease diagnosis.
• Traditional detection methods often require complex procedures and long analysis times.
• Nanomaterials offer unique properties for enhancing biosensor performance.

Purpose of the Study:

• To prepare a novel ionic liquid functionalized graphene sheet loaded with gold nanoparticles (IL-GS-AuNPs) nanocomposite.
• To fabricate a facile and sensitive electrochemical immunosensor using the IL-GS-AuNPs nanocomposite.
• To evaluate the immunosensor's performance for detecting Carcinoembryonic antigen (CEA) in clinical serum samples.

Main Methods:

• Synthesis of IL-GS via electrochemical exfoliation of graphite in ionic liquid.
• Loading of gold nanoparticles (AuNPs) onto the IL-GS to form the IL-GS-AuNPs nanocomposite.
• Fabrication of an electrochemical immunosensor by immobilizing antibodies onto the IL-GS-AuNPs.
• Detection of CEA using cyclic voltammetry and electrochemical impedance spectroscopy.

Main Results:

• The IL-GS-AuNPs nanocomposite exhibited enhanced conductivity and a large specific surface area.
• The developed immunosensor demonstrated a wide linear detection range (LDR) from 1 fg mL⁻¹ to 100 ng mL⁻¹ for CEA.
• An ultra-low limit of detection (LOD) of 0.1 fg mL⁻¹ (S/N=3) was achieved for CEA detection.
• The immunosensor showed good agreement with clinical immunoassay and ELISA results for serum samples.

Conclusions:

• The IL-GS-AuNPs nanocomposite is a promising platform for developing highly sensitive electrochemical immunosensors.
• The fabricated immunosensor offers a sensitive, rapid, and reliable method for CEA detection.
• This technology holds potential for application in clinical diagnostics and early cancer screening.