Shell-engineered chiroplasmonic assemblies of nanoparticles for zeptomolar DNA detection

Area of Science:

• Nanotechnology
• Plasmonics
• Biophysics

Background:

• Metallic nanoparticles (NPs) can form chiral structures when bridged by DNA.
• The non-spherical shape of NPs and their arrangement contribute to this chirality.
• Chiroplasmonic properties offer unique optical responses.

Purpose of the Study:

• To engineer multimetal heterodimers with enhanced chiroplasmonic activity.
• To investigate the application of these heterodimers in sensitive DNA detection.
• To optimize light-plasmon coupling for improved detection sensitivity.

Main Methods:

• Fabrication of gold and silver shelled NP heterodimers.
• Spectral modulation of chiroplasmonic bands in the 400-600 nm range.
• Utilizing polymerase chain reaction (PCR) for DNA detection.

Main Results:

• Achieved significantly enhanced optical activity with g-factors up to 1.21 × 10(-2).
• Demonstrated PCR-based DNA detection at the zeptomolar level.
• Observed improved base pairing and enhanced photon-plasmon coupling.

Conclusions:

• Multimetal NP heterodimers are effective chiroplasmonic sensors.
• Optimized coupling with photon spin angular momentum enhances detection sensitivity.
• This approach offers a highly sensitive method for DNA detection.