Enhanced Plasmonic Particle Trapping Using a Hybrid Structure of Nanoparticles and Nanorods

Area of Science:

• Nanotechnology
• Plasmonics
• Biophysics

Background:

• Localized surface plasmon resonance (LSPR) is crucial for optical trapping.
• Hybrid nanostructures can enhance plasmonic properties.
• Zinc oxide nanorods (ZnONRs) offer unique optical and dielectric properties.

Purpose of the Study:

• To demonstrate plasmon-enhanced particle trapping using a novel hybrid ZnONR/AuNP structure.
• To investigate the synergistic effects of ZnONRs and gold nanoparticles (AuNPs) on LSPR.
• To analyze the role of ZnONRs in enhancing particle-trapping velocity.

Main Methods:

• Fabrication of a hybrid ZnONR/AuNP structure.
• Experimental characterization of plasmon-enhanced particle trapping.
• Numerical simulations to analyze LSPR-induced photophysical processes (plasmonic heating, near-field enhancement), scattered electric field, Poynting vector, and temperature gradients.

Main Results:

• The hybrid ZnONR/AuNP structure exhibited intensified LSPR.
• Numerical analysis confirmed improved plasmonic heating and near-field enhancement due to ZnONRs.
• Successful trapping of polystyrene microparticles and Escherichia coli cells was achieved.
• The hybrid substrate demonstrated enhanced trapping performance compared to gold nanoislands alone.

Conclusions:

• The hybrid ZnONR/AuNP structure effectively enhances plasmon-enhanced particle trapping.
• The synergistic effect between ZnONRs and AuNPs, driven by ZnO's dielectric properties and nanorod geometry, is key to improved performance.
• This technology holds potential for applications in microparticle manipulation and cell sorting.