Four-Channel Photothermal Plate Reader for High-Throughput Nanoparticle-Amplified Immunoassay

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Immunosensing

Background:

• Microplate-based photothermal detection offers sensitive biomarker quantification.
• Current methods often suffer from low sample throughput and long assay times.
• Efficient detection of C-reaction protein (CRP) is crucial for diagnosing inflammation and cardiovascular risk.

Purpose of the Study:

• To enhance the sample throughput of microplate-based photothermal detection.
• To develop a rapid, automated immunoassay for CRP detection.
• To improve the efficiency and reduce the cost of biomarker quantification.

Main Methods:

• Utilized a semicylindrical prism to expand a laser source for simultaneous illumination of multiple wells.
• Employed four epoxy-coated thermocouples with a 96-well microplate for parallel immunoassays.
• Integrated a translational/elevator stage for automated assay cycles, including rinsing and drying.

Main Results:

• Achieved a sample throughput of 8.62 minutes per sample, a significant improvement over manual methods.
• Demonstrated excellent well-to-well (RSD = 1.3%) and cycle-to-cycle (RSD = 4.0%) reproducibility.
• Obtained a low limit of detection for CRP (0.52 ng/mL or 4.33 pM), suitable for clinical diagnostics.

Conclusions:

• The developed automated, high-throughput photothermal assay is cost-effective and robust.
• This method enables rapid and sensitive quantification of biomarkers like CRP in clinical samples.
• The system shows excellent agreement with established immunoturbidimetric methods, validating its clinical utility.