Numerical investigation of the plasmonic properties of bare and cysteine-functionalized silver nanoparticles

Anikó Szalai; Áron Sipos; Edit Csapó; Viktória Hornok; László Tóth; Mária Csete; Imre Dékány

doi:10.1117/12.894015

20 September 2011 Numerical investigation of the plasmonic properties of bare and cysteine-functionalized silver nanoparticles

Anikó Szalai, Áron Sipos, Edit Csapó, Viktória Hornok, László Tóth, Mária Csete, Imre Dékány

Author Affiliations +

Proceedings Volume 8096, Plasmonics: Metallic Nanostructures and Their Optical Properties IX; 80963B (2011) https://doi.org/10.1117/12.894015
Event: SPIE NanoScience + Engineering, 2011, San Diego, California, United States

Abstract

The absorption spectra of different aqueous dispersions containing silver nanoparticles were computed by finite element method and compared to spectra determined by UV-Visible spectroscopy. This comparative study proved that the spectrum measured on the aqueous dispersion of bare silver nanoparticles with absorptance maximum at λ_meas = 391 nm corresponds to the characteristic UV surface plasmon band of spherical nanoparticles with 8.25 nm diameter. The presence of aggregates in aqueous dispersions resulted in splitting on the spectrum, when the surface of the silver nanoparticles with c_Ag = 2×10^-4 M concentration was functionalized by L-cysteine with cCys=5.7×10^-6 M concentration. The simplest aggregate-geometries that exhibit resonance at the measured absorptance maxima were determined by varying the number of silver nanoparticles, and the inter-particle distance in linear chains, and taking 0.45 nm thick cysteine-shell into account. The FEM computations proved that the primary maxima in the UV involve quadrupolar modes, while the secondary maxima red-shifted to λ_{meas_2}=567 nm at pH=2.98 and λ_{meas_2}'=588 nm at pH=4.92 originate from coupled dipolar plasmon resonances on extended aggregates aligned along the E-field oscillation direction. The non-aggregated particles and the aggregates rotated with respect to the E-field oscillation direction significantly contribute to the UV peak.

Citation Download Citation

Anikó Szalai, Áron Sipos, Edit Csapó, Viktória Hornok, László Tóth, Mária Csete, and Imre Dékány "Numerical investigation of the plasmonic properties of bare and cysteine-functionalized silver nanoparticles", Proc. SPIE 8096, Plasmonics: Metallic Nanostructures and Their Optical Properties IX, 80963B (20 September 2011); https://doi.org/10.1117/12.894015

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available