Chitosan-Modified Gold Nanoparticle-Based Electrochemical Immunosensor for C-Reactive Protein Detection

Area of Science:

• Electrochemistry
• Biosensors
• Nanotechnology
• Biomarker Detection

Background:

• C-reactive protein (CRP) is a critical biomarker for inflammation and infection.
• Existing detection methods may lack sensitivity, selectivity, or point-of-care suitability.
• Gold nanoparticles (AuNPs) offer unique electrochemical properties for biosensor development.

Purpose of the Study:

• To develop a sensitive and selective electrochemical immunosensor for CRP detection.
• To leverage gold nanoparticles (AuNPs) for enhanced sensor performance.
• To evaluate the immunosensor's potential for point-of-care (POC) applications.

Main Methods:

• Fabrication of a screen-printed carbon electrode (SPCE) modified with AuNPs.
• Immobilization of anti-CRP antibodies using L-cysteine SAM and EDC/sulfo-NHS chemistry.
• Electrochemical characterization using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV).

Main Results:

• The immunosensor demonstrated a low limit of detection (LOD) of 0.16 µg/mL and a wide linear range (5-100 µg/mL).
• High selectivity against 13 interferents and good reproducibility (RSD 3.69%) were achieved.
• The sensor exhibited excellent stability (retaining >95% signal after 15 days) and regeneration efficiency (97% over 7 cycles).

Conclusions:

• The developed electrochemical immunosensor provides a sensitive, selective, and stable platform for CRP detection.
• The sensor's performance characteristics make it suitable for reliable CRP quantification.
• The proposed immunosensor holds significant potential for cost-effective and user-friendly point-of-care diagnostics.