Lipid-lipid interactions in aminated reduced graphene oxide interface for biosensing application.

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Cardiovascular disease risk is closely linked to low-density lipoprotein (LDL) cholesterol levels.
• Accurate and sensitive detection of LDL cholesterol is crucial for early diagnosis and management.
• Existing detection methods may lack sensitivity, speed, or require complex sample preparation.

Purpose of the Study:

• To develop a label-free biosensor for the sensitive detection of LDL cholesterol.
• To functionalize an aminated reduced graphene oxide (NH2-rGO) interface with anti-apolipoprotein B 100 (AAB).
• To investigate the performance characteristics of the developed immunosensor for lipid detection.

Main Methods:

• Fabrication of a label-free biosensor using anti-apolipoprotein B 100 functionalized NH2-rGO.
• Covalent immobilization of AAB onto the NH2-rGO surface via EDC/NHS coupling chemistry.
• Electrochemical impedance spectroscopy (EIS) for investigating lipid-lipid interactions and sensor performance.
• Characterization using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-visible, and electrochemical techniques.

Main Results:

• The immunosensor demonstrated excellent sensitivity (612 Ω mg(-1) dL cm(-2)) and a low detection limit of 5 mg/dL for LDL.
• A rapid response time of 250 s was achieved.
• Kinetic parameters including association (1.66 M⁻¹ s⁻¹), dissociation (0.6 s⁻¹), and equilibrium rate constants (2.77 M⁻¹) were determined.
• The biosensor exhibited good long-term stability and reproducibility.

Conclusions:

• The developed label-free biosensor offers an efficient platform for the sensitive and reproducible detection of LDL cholesterol.
• The NH2-rGO based immunosensor shows promise for clinical applications in lipid analysis.
• The study highlights the potential of functionalized graphene-based materials in biosensing for cardiovascular risk assessment.