Self-Validated Homogeneous Immunoassay by Single Nanoparticle in-Depth Scrutinization
Zili Huang1, Chaoqun Wang1, Rui Liu1
1Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry , Sichuan University , Chengdu , Sichuan 610064 , China.
Insights
This study introduces a self-validated homogeneous immunoassay for accurate disease biomarker analysis. It overcomes matrix effects using single gold nanoparticles and ICP-MS, ensuring reliable clinical results.
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.
Abstract:
The most convenient method for the clinical routine analysis of disease biomarkers is homogeneous immunoassay, which minimizes the requirements for automation and time-/lab-consumption. Despite great success, because sample constituents are not removed by a separation or washing step, a major challenge in conducting homogeneous immunoassays for the practical application is the matrix effect-related inaccuracy. Herein, to guarantee an accurate quantification, a self-validated homogeneous immunoassay was proposed, by simultaneously scrutinizing both frequency and intensity of single gold nanoparticles. The two analytical modes of single particle inductively coupled plasma mass spectrometry (ICPMS) correlated well with each other, resulting in a self-validation mechanism for the accurate immunoassay. Both two modes of the proposed method provided linear ranges of 2 orders of magnitude and LODs of pM level. Thanks to the self-validated strategy and the high tolerance of the matrix effect of ICPMS, the proposed homogeneous immunoassay was successfully demonstrated in a series of human serum samples, with results in good accordance with clinical routine methods.
