A label-free nanostructured plasmonic biosensor based on Blu-ray discs with integrated microfluidics for sensitive...

Area of Science:

• Plasmonics
• Nanotechnology
• Biosensing

Background:

• Nanostructure-based plasmonic biosensors are promising for portable optical biosensor platforms.
• They offer benefits in integration, miniaturization, multiplexing, and real-time label-free detection.

Purpose of the Study:

• To develop a simple, integrated nanoplasmonic sensor utilizing commercial Blu-ray disc nanostructures.
• To enhance sensor performance through oblique-angle light incidence and integration with microfluidics.

Main Methods:

• Fabrication of sensors with 50nm and 100nm gold film thicknesses.
• Optical characterization using reflectance measurements with varying oblique angles of incident light.
• Integration with microfluidics for a compact, portable prototype.

Main Results:

• Enhanced sensitivity and narrowed resonant linewidths observed with increased light incidence angle, potentially due to Fano resonant modes.
• Achieved a figure of merit (FOM) up to 35 RIU^-1 and a bulk limit of detection (LOD) of 6.3×10^-6 RIU.
• Demonstrated label-free detection of antibodies against GTF2b protein (colorectal cancer marker) with a picomolar LOD, and feasibility in human serum.

Conclusions:

• The developed Blu-ray disc-based nanoplasmonic sensor offers improved performance and potential for portable, label-free biosensing.
• The integration with microfluidics results in a facile, miniaturized, and potentially portable biosensing system.
• The sensor shows promise for detecting cancer biomarkers and analyzing biological samples.