Highly sensitive homogenous chemiluminescence immunoassay using gold nanoparticles as label

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Diagnostics

Background:

• Homogeneous immunoassays offer advantages over heterogeneous methods in diagnostics, including reduced sample and reagent use, faster analysis, and improved portability.
• Gold nanoparticles (AuNPs) exhibit catalytic properties that can be harnessed for sensitive detection methods.

Purpose of the Study:

• To develop a universal platform for homogeneous immunoassay using gold nanoparticles (AuNPs).
• To detect human immunoglobulin G (IgG) as a model analyte with enhanced sensitivity and speed.

Main Methods:

• Utilized the catalytic activity of AuNPs on a luminol-AgNO3 chemiluminescence (CL) reaction.
• Induced aggregation of antibody-functionalized AuNPs upon antigen-antibody immunoreaction to enhance catalytic activity.
• Generated CL signal without separation steps upon addition of a trigger solution.

Main Results:

• The aggregated AuNPs showed significantly enhanced catalytic activity on the luminol-AgNO3 CL reaction.
• The CL intensity was directly correlated with the quantity of human IgG.
• Achieved a detection limit as low as 3 pg/mL for IgG.
• Demonstrated superior sensitivity compared to previously reported AuNPs-based CL immunoassays for IgG.

Conclusions:

• The developed universal platform enables sensitive and rapid homogeneous immunoassay detection.
• This AuNPs-based CL strategy provides a promising approach for advanced medical diagnostics.
• The method's efficiency in sample and reagent consumption aligns with modern diagnostic needs.