Chiral Plasmonic Shells: High-Performance Metamaterials for Sensitive Chiral Biomolecule Detection

Area of Science:

• Plasmonics and Nanophotonics
• Materials Science
• Chiroptical Spectroscopy

Background:

• Low-cost, large-area chiral metamaterials (CMs) are crucial for applications like chiral biosensors and nanophotonic emitters.
• Existing fabrication methods, such as glancing angle deposition (GLAD) on colloidal particles, face challenges in achieving uniformity over macroscopic scales.

Purpose of the Study:

• To develop a uniform, large-area fabrication method for chiral plasmonic shells (CPSs) with controlled structural handedness.
• To investigate the chiroptical properties and sensor performance of the fabricated CPSs for chiral molecule detection.

Main Methods:

• Interface-mediated self-assembly was used to create uniform large-area colloidal particle arrays.
• Glancing angle deposition (GLAD) precisely controlled the structural handedness of chiral plasmonic shells (CPSs).
• Systematic investigations optimized the interplay between peak and null point resonances in CPSs.

Main Results:

• Fabricated uniform large-area CPSs exhibiting strong chiroptical signals due to twisted currents.
• Achieved a balance between strong chiroptical response and high transmittance.
• Demonstrated excellent chiral sensing performance with record consistency parameters (U=3.77 for null points, U=0.0867 for peaks), significantly outperforming previous CMs.

Conclusions:

• The developed method enables the fabrication of uniform, large-area CMs with precisely controlled chirality.
• The CPSs exhibit strong chiroptical effects and superior chiral sensing capabilities due to uniform superchiral fields.
• This work paves the way for practical applications of CMs in sensitive chiral detection.