Electro-Optical Biosensor Based on Embedded Double-Monolayer of Graphene Capacitor in Polymer Technology

Area of Science:

• Photonics
• Materials Science
• Nanotechnology

Background:

• Interferometric devices are crucial for sensitive measurements.
• Graphene's unique electro-optical properties offer tunable absorption.
• Polymer photonics provides a low-cost platform for optical devices.

Purpose of the Study:

• To present a polymer-based electro-optical device for biosensing.
• To integrate a graphene capacitor for tunable optical properties.
• To enhance sensitivity and light-matter interaction for biosensing applications.

Main Methods:

• Fabrication of an interferometric polymer device with embedded graphene.
• Application of external voltage to tune graphene's Fermi level and electro-optical properties.
• Utilizing evanescent wave coupling for maximized light-graphene interaction.

Main Results:

• Achieved tunable waveguide absorption via external voltage control.
• Demonstrated large phase changes in the interferometer output.
• Obtained an optimal interaction length of 1.24 cm for a cladding refractive index of 1.33.
• Showcased an absorption change of 129 dB/mm.

Conclusions:

• The developed device offers significantly increased sensitivity for biosensing.
• The combination of polymer photonics and graphene enables a low-cost biosensing solution.
• Potential for application in Point of Care (PoC) diagnostic platforms.