Tunable resonant graphene plasmons for mid-infrared biosensing.

Area of Science:

• Plasmonics
• Nanotechnology
• Biophysics

Background:

• Surface plasmons (SPs) are collective oscillations of electrons at a metal-dielectric interface.
• Graphene's unique electronic properties enable tunable SPs in the mid-infrared (mid-IR) region.
• Nanoscale biosensing requires high sensitivity and specificity for detecting biomolecules like proteins.

Purpose of the Study:

• To investigate tunable resonant surface plasmons based on graphene nanoribbons for nanoscale protein detection.
• To explore the potential of graphene plasmons for probing protein chemical vibrations.
• To assess the feasibility of graphene plasmon-based devices for future nanoscale biosensing.

Main Methods:

• Fabrication of graphene nanoribbons.
• Excitation and characterization of resonant surface plasmons in the mid-IR region.
• Measurement of refractive index changes upon interaction with nanoscale protein molecules.

Main Results:

• Demonstrated strong electric field confinement of graphene plasmons due to their 2D nature.
• Achieved high sensitivity in detecting refractive index changes of nanoscale protein molecules.
• Showcased Fermi level controlled resonant SPs for nanoscale light control and probing of chemical vibrations.

Conclusions:

• Graphene nanoribbon-based SPs offer a highly sensitive platform for nanoscale protein detection in the mid-IR.
• Tunable spectral selectivity and sensitivity make these devices promising for biosensing.
• The ability to probe chemical vibrations opens new avenues for molecular analysis.