Disk-based one-dimensional photonic crystal slabs for label-free immunosensing

Area of Science:

• Photonics and Nanotechnology
• Biomedical Engineering
• Optical Sensing

Background:

• One-dimensional photonic crystal slabs exhibit guided-mode resonance, creating bandgaps sensitive to surface refractive index changes.
• Existing biosensing technologies can be costly and complex, limiting widespread application.

Purpose of the Study:

• To develop and validate low-cost, label-free optical biosensors utilizing one-dimensional photonic crystal slabs.
• To leverage the nanostructure of Blu-ray disks for enhanced biosensing capabilities.

Main Methods:

• Fabrication of one-dimensional photonic crystal slabs from Blu-ray disk nanostructures.
• Coating the structures with titanium dioxide (TiO2) to induce guided-mode resonance.
• Experimental validation of optical properties and bioanalytical performance through immunoassays.

Main Results:

• Demonstrated guided-mode resonance in TiO2-coated polycarbonate nanostructures.
• Achieved sensitive detection of Immunoglobulin G (IgG), C-reactive protein (CRP), and lactate dehydrogenase (LDH).
• Reported detection limits of 0.1 nM for IgG, 87 nM for CRP, and 13 nM for LDH.

Conclusions:

• Repurposed Blu-ray disks offer a viable, low-cost platform for fabricating effective optical biosensors.
• The developed biosensors show significant promise for portable, label-free detection of clinically relevant biomarkers.
• This approach integrates photonic crystal technology with accessible materials for next-generation diagnostics.