Periodic plasmonic enhancing epitopes on a whispering gallery mode biosensor.

Area of Science:

• Nanotechnology
• Biosensing
• Plasmonics

Background:

• Whispering gallery mode (WGM) biosensors offer high sensitivity for detecting analytes.
• Current methods face challenges in analyte capture efficiency and signal self-referencing.
• Plasmonic enhancement is a promising strategy to overcome these limitations.

Purpose of the Study:

• To develop a novel WGM biosensor design for enhanced nanoparticle sensing.
• To achieve plasmonic enhancement and self-referencing capabilities.
• To increase the capture rate of analytes using antibody-functionalized gold nanoparticles.

Main Methods:

• Attaching a periodic array of gold nanoparticles (epitopes) to the equator of WGM resonators.
• Utilizing various WGM resonator platforms including silicon/silica rings, disks, and capillaries.
• Designing the optical phase difference between epitopes to be an integer multiple of pi for signal additivity.

Main Results:

• Demonstrated plasmonic enhancement of nanoparticle sensing.
• Achieved self-referencing capabilities for improved signal interpretation.
• Increased analyte capture rate due to antibody-functionalized plasmonic epitopes.

Conclusions:

• The proposed method offers a simple and effective way to enhance WGM biosensor performance.
• This approach is versatile and applicable to various WGM resonator types.
• The design facilitates independent addition of wavelength shifts from individual binding events, simplifying data analysis.