Related Experiment Video
Updated: May 3, 2026
09:29
Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation
Published on: September 27, 2011
11.5K
Enhanced Sensitivity of Delocalized Plasmonic Nanostructures
Madu N Mendis1, Himadri S Mandal1, David H Waldeck1
1Department of Chemistry, University of Pittsburgh, 219 Parkman Street, Pittsburgh PA 15260, USA.
The Journal of Physical Chemistry. C, Nanomaterials and Interfaces
|January 29, 2014
Summary
Delocalized surface plasmon resonance (DSPR) was observed in silver nanoparticle chains. Shorter nanoparticle spacing and longer chains enhanced this effect, showing increased sensitivity over localized surface plasmon resonance (LSPR).
Area of Science:
- Plasmonics and Nanophotonics
- Materials Science
- Condensed Matter Physics
Background:
- Surface plasmon resonance (SPR) is a phenomenon involving the oscillation of conduction electrons on metal surfaces.
- Localized surface plasmon resonance (LSPR) occurs in nanoparticles, while delocalized surface plasmon resonance (DSPR) involves coupled oscillations in nanoparticle arrays.
- Understanding DSPR is crucial for developing advanced optical devices and sensors.
Purpose of the Study:
- To investigate the delocalized surface plasmon resonance (DSPR) phenomenon in linear chains of silver nanoparticles.
- To examine the influence of chain length and inter-nanoparticle distance on DSPR characteristics.
- To compare the sensitivity of DSPR with LSPR to dielectric environment changes.
Main Methods:
- Fabrication of linear chains of square-shaped silver nanoparticles.
- Measurement of transmission spectra of nanoparticle chains.
- Analysis of extinction peaks in relation to nanoparticle spacing and light polarization.
- Theoretical modeling using a tight-binding model for coupled chains.
- Finite-difference time-domain (FDTD) calculations to simulate electric field enhancement.
Main Results:
- Observation of new, red-shifted extinction peaks in transmission spectra, characteristic of DSPR.
- Strong dependence of DSPR peaks on inter-nanoparticle spacing and light polarization.
- Increased DSPR feature strength with decreasing spacing and increasing chain length, indicating enhanced coupling.
- Significant electric field enhancement between nanoparticles in the chain, confirmed by FDTD.
- DSPR demonstrated higher sensitivity to dielectric changes compared to LSPR.
Conclusions:
- The study confirms the presence of DSPR in linear silver nanoparticle chains.
- Inter-particle coupling, influenced by spacing and chain length, is the origin of the observed DSPR.
- The enhanced sensitivity of DSPR to dielectric variations offers potential for novel sensing applications.
