Optical waveguide biosensors constructed with subwavelength gratings.

Area of Science:

• Biophotonics
• Biosensing Technology
• Surface Chemistry

Background:

• Label-free biosensing is crucial for real-time analysis of biomolecular interactions.
• Optical waveguide sensors offer high sensitivity for detecting molecular binding events.
• Subwavelength gratings can enhance the performance of optical biosensors.

Purpose of the Study:

• To develop and characterize a subwavelength diffraction-grating-coupled waveguide biosensor.
• To analyze biomolecular interactions in real time without extrinsic labeling.
• To investigate the kinetic response of antibody-protein G interactions.

Main Methods:

• Theoretical analysis of subwavelength optical waveguide biosensor.
• Design and fabrication of a biosensor with a narrow reflection resonance spectrum.
• Real-time monitoring of resonance wavelength shifts upon biomolecular binding.

Main Results:

• Demonstrated a label-free optical waveguide biosensor for biomolecular interaction analysis.
• Achieved enhanced detection resolution due to a narrow reflection resonance spectrum.
• Established a detection limit of approximately 10(-5) refractive-index units.
• Successfully studied the dynamic response of antibody-protein G interactions.

Conclusions:

• The subwavelength diffraction-grating-coupled waveguide biosensor enables label-free, real-time kinetic analysis of biomolecular interactions.
• The developed sensor exhibits high detection resolution and sensitivity.
• This technology holds promise for various applications in biomolecular research and diagnostics.