Multiplexed cancer biomarker detection using quartz-based photonic crystal surfaces

Area of Science:

• Biophotonics
• Nanotechnology
• Biomedical Engineering

Background:

• Photonic crystals (PCs) offer unique optical properties for biosensing.
• Existing biosensing platforms face challenges in sensitivity and quantification accuracy.
• Cancer biomarker detection is crucial for early diagnosis and treatment monitoring.

Purpose of the Study:

• To demonstrate a photonic crystal (PC) surface as a high-sensitivity platform for detecting multiple cancer biomarker antigens.
• To develop a sandwich enzyme-linked immunosorbent assay (ELISA) microarray utilizing PC properties.
• To enhance fluorescence detection and enable label-free quantification of biomarkers.

Main Methods:

• Fabrication of a quartz-based PC structure using nanoimprint lithography.
• Development of a detection instrument with fluorescence and label-free imaging modalities.
• Implementation of an angle-scanning laser approach for optimizing fluorescence enhancement and compensating for surface variations.

Main Results:

• The PC surface demonstrated high sensitivity for detecting 21 cancer biomarker antigens.
• Simultaneous fluorescence enhancement and label-free quantification of antibody capture spots were achieved.
• The angle-scanning illumination reduced assay variability by 20-99% compared to conventional microscopy.
• Biomarkers were detected at concentrations as low as 2.1 pg/mL with a three-log quantitative range.

Conclusions:

• The PC surface serves as a robust and sensitive platform for multiplexed cancer biomarker detection.
• The developed detection instrument and methods significantly improve assay precision and reduce detection limits.
• This technology holds promise for advancing early cancer diagnostics and personalized medicine.