From tunable core-shell nanoparticles to plasmonic drawbridges: Active control of nanoparticle optical properties

Chad P Byers; Hui Zhang; Dayne F Swearer; Mustafa Yorulmaz; Benjamin S Hoener; Da Huang; Anneli Hoggard; Wei-Shun Chang; Paul Mulvaney; Emilie Ringe; Naomi J Halas; Peter Nordlander; Stephan Link; Christy F Landes

doi:10.1126/sciadv.1500988

From tunable core-shell nanoparticles to plasmonic drawbridges: Active control of nanoparticle optical properties

Sci Adv. 2015 Dec 4;1(11):e1500988. doi: 10.1126/sciadv.1500988. eCollection 2015 Dec.

Authors

Affiliations

¹ Smalley-Curl Institute Applied Physics Program, Rice University, Houston, TX 77005, USA. ; Department of Chemistry, Rice University, Houston, TX 77005, USA.
² Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA.
³ Department of Chemistry, Rice University, Houston, TX 77005, USA.
⁴ School of Chemistry and Bio21 Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
⁵ Department of Chemistry, Rice University, Houston, TX 77005, USA. ; Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA.
⁶ Smalley-Curl Institute Applied Physics Program, Rice University, Houston, TX 77005, USA. ; Department of Chemistry, Rice University, Houston, TX 77005, USA. ; Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA. ; Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA. ; Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
⁷ Smalley-Curl Institute Applied Physics Program, Rice University, Houston, TX 77005, USA. ; Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA. ; Materials Science and Nanoengineering, Rice University, Houston, TX 77005, USA. ; Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.
⁸ Smalley-Curl Institute Applied Physics Program, Rice University, Houston, TX 77005, USA. ; Department of Chemistry, Rice University, Houston, TX 77005, USA. ; Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.

Abstract

The optical properties of metallic nanoparticles are highly sensitive to interparticle distance, giving rise to dramatic but frequently irreversible color changes. By electrochemical modification of individual nanoparticles and nanoparticle pairs, we induced equally dramatic, yet reversible, changes in their optical properties. We achieved plasmon tuning by oxidation-reduction chemistry of Ag-AgCl shells on the surfaces of both individual and strongly coupled Au nanoparticle pairs, resulting in extreme but reversible changes in scattering line shape. We demonstrated reversible formation of the charge transfer plasmon mode by switching between capacitive and conductive electronic coupling mechanisms. Dynamic single-particle spectroelectrochemistry also gave an insight into the reaction kinetics and evolution of the charge transfer plasmon mode in an electrochemically tunable structure. Our study represents a highly useful approach to the precise tuning of the morphology of narrow interparticle gaps and will be of value for controlling and activating a range of properties such as extreme plasmon modulation, nanoscopic plasmon switching, and subnanometer tunable gap applications.

Keywords: Nanoparticles; active plasmonics; charge transfer plasmon; interparticle gaps; materials science; optical properties.