Issue 12, 2016

Optical extinction and scattering cross sections of plasmonic nanoparticle dimers in aqueous suspension

Abstract

Absolute extinction and scattering cross sections for gold nanoparticle dimers were determined experimentally using a chemometric approach involving singular-value decomposition of the extinction and scattering spectra of slowly aggregating gold nanospheres in aqueous suspension. Quantitative spectroscopic data on plasmonic nanoparticle assemblies in liquid suspension are rare, in particular for particles larger than 40 nm, and in this work we demonstrate how such data can be obtained directly from the aggregating suspension. Our method can analyse, non invasively, the evolution of several sub-populations of nanoparticle assemblies. It may be applied to other self-assembling nanoparticle systems with an evolving optical response. The colloidal systems studied here are based on 20, 50 and 80 nm gold nanospheres in aqueous solutions containing sodium lipoate. In these systems, the reversible dimerisation process can be controlled using pH and ionic strength, and this control is rationalised in terms of DLVO theory. The dimers were identified in suspension by their translational and rotational diffusion through scattering correlation spectroscopy. Moreover, their gigadalton molecular weight was measured using electrospray charge-detection mass spectrometry, demonstrating that mass spectrometry can be used to study nanoparticles assemblies of very high molecular mass. The extinction and scattering cross sections calculated in the discrete-dipole approximation (DDA) agree very well with those obtained experimentally using our approach.

Graphical abstract: Optical extinction and scattering cross sections of plasmonic nanoparticle dimers in aqueous suspension

Supplementary files

Article information

Article type
Paper
Submitted
01 Feb 2016
Accepted
23 Feb 2016
First published
03 Mar 2016

Nanoscale, 2016,8, 6555-6570

Optical extinction and scattering cross sections of plasmonic nanoparticle dimers in aqueous suspension

M. Loumaigne, C. Midelet, T. Doussineau, P. Dugourd, R. Antoine, M. Stamboul, A. Débarre and M. H. V. Werts, Nanoscale, 2016, 8, 6555 DOI: 10.1039/C6NR00918B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements