Self-Validated Homogeneous Immunoassay by Single Nanoparticle in-Depth Scrutinization

Area of Science:

• Analytical Chemistry
• Biomarker Detection
• Nanotechnology

Background:

• Homogeneous immunoassays offer convenient clinical biomarker analysis but suffer from matrix effect-induced inaccuracies.
• Accurate quantification in complex biological samples remains a challenge for current homogeneous immunoassay methods.

Purpose of the Study:

• To develop a self-validated homogeneous immunoassay for accurate disease biomarker quantification.
• To address and mitigate the matrix effect in homogeneous immunoassays.

Main Methods:

• Simultaneous analysis of single gold nanoparticle frequency and intensity using single particle inductively coupled plasma mass spectrometry (ICP-MS).
• Development of a self-validation mechanism through correlated analytical modes of ICP-MS.
• Application of the method to human serum samples.

Main Results:

• The two ICP-MS analytical modes demonstrated good correlation, establishing a self-validation mechanism.
• The proposed method achieved linear ranges of 2 orders of magnitude and picomolar (pM) level limits of detection (LODs).
• Successful demonstration in human serum samples, showing results consistent with routine clinical methods.

Conclusions:

• The self-validated homogeneous immunoassay effectively guarantees accurate quantification by overcoming matrix effects.
• The high matrix effect tolerance of ICP-MS combined with the self-validation strategy enables reliable biomarker analysis in clinical samples.
• This approach offers a robust solution for routine clinical diagnostics requiring precise immunoassay results.