An improved gold nanoparticle probe-based assay for HCV core antigen ultrasensitive detection

Area of Science:

• Biotechnology
• Nanotechnology
• Medical Diagnostics

Background:

• Hepatitis C virus (HCV) infection poses a significant global health challenge.
• Accurate and sensitive detection of HCV core antigen is crucial for diagnosis and management.
• Existing diagnostic methods like ELISA have limitations in sensitivity.

Purpose of the Study:

• To develop and validate a novel gold nanoparticle probe-based assay (GNPA) for ultrasensitive detection of HCV core antigen.
• To enhance the sensitivity and reliability of HCV core antigen detection compared to traditional methods.
• To reduce interference from unbound reagents in the assay.

Main Methods:

• Development of a gold nanoparticle probe (NP) labeled with anti-HCV core antigen polyclonal antibodies and barcode DNA.
• Utilizing DNA enzyme to degrade unbound barcode DNAs, minimizing background noise.
• Employing magnetic microparticles probe (MMP) coated with monoclonal antibodies for antigen capture.
• Formation of a sandwich immuno-complex and subsequent detection via TaqMan probe-based real-time fluorescence PCR.

Main Results:

• Achieved an ultrasensitive detection limit of 1 fg/ml for HCV core antigen, a significant improvement over ELISA's 2 ng/ml.
• Demonstrated high assay precision with intra-assay coefficients of variation (CV) ranging from 0.22-2.62% and inter-assay CV from 1.92-3.01%.
• The improved GNPA effectively decreased interference from unbound barcode DNAs.

Conclusions:

• The developed GNPA provides a highly sensitive and reliable method for detecting HCV core antigen.
• This assay represents a significant advancement over conventional diagnostic techniques for HCV.
• The GNPA offers a promising new approach for the clinical detection of Hepatitis C virus.