Plasmonic interferometric sensor arrays for high-performance label-free biomolecular detection

Area of Science:

• Nanotechnology
• Biophysics
• Plasmonics

Background:

• Surface plasmon polaritons (SPPs) are crucial for plasmonic sensing.
• Existing biosensors face limitations in sensitivity, footprint, and cost.

Purpose of the Study:

• To demonstrate a plasmonic interferometric biosensor for phase-sensitive biomolecular detection.
• To engineer SPP interference for enhanced sensing capabilities.

Main Methods:

• Fabrication of circular aperture-groove nanostructures on a gold film.
• Utilizing SPP interference for phase-sensitive detection.
• Employing structural tuning to control plasmon line shape.

Main Results:

• Achieved high-contrast spectral fringes with narrow linewidth and large amplitude.
• Demonstrated sensitive detection of protein surface coverage as low as 0.4 pg mm(-2).
• Obtained a high sensing figure of merit (FOM*) of 146, surpassing previous plasmonic biosensors.

Conclusions:

• The developed biosensor offers a simpler, miniaturized, and cost-effective alternative to commercial systems.
• The intensity interrogation method combined with CCD imaging enables high-throughput array sensing.
• The novel sensing scheme facilitates ultrasensitive, high-throughput biomolecular detection.