title: Tuning Localized Surface Plasmon Resonance Wavelengths of Silver Nanoparticles by Mechanical Deformation.
abstract: We describe a simple technique to alter the shape of silver nanoparticles (AgNPs) by rolling a glass tube over them to mechanically compress them. The resulting shape change in turn induces a red-shift in the localized surface plasmon resonance (LSPR) scattering spectrum and exposes new surface area. The flattened particles were characterized by optical and electron microscopy, single nanoparticle scattering spectroscopy, and surface enhanced Raman spectroscopy (SERS). AFM and SEM images show that the AgNPs deform into discs; increasing the applied load from 0 to 100 N increases the AgNP diameter and decreases the height. This deformation caused a dramatic red shift in the nanoparticle scattering spectrum and also generated new surface area to which thiolated molecules could attach as evident from SERS measurements. The simple technique employed here requires no lithographic templates and has potential for rapid, reproducible, inexpensive and scalable tuning of nanoparticle shape, surface area, and resonance while preserving particle volume.
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634.
authors.forename: Fathima S
authors.initials: FS
authors.lastname: Ameer
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634; Department of Mechanical Engineering, Clemson University, Clemson SC 29634.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Varahagiri
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634; Department of Electrical and Computer Engineering, Clemson University, Clemson SC 29634.
authors.forename: Donald W
authors.initials: DW
authors.lastname: Benza
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Willett
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634.
authors.forename: Fenglin
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634.
authors.forename: George
authors.initials: G
authors.lastname: Chumanov
authors.affiliation: Department of Chemistry, Clemson University, Clemson SC 29634; Center for Optical Materials Science and Engineering Technologies (COMSET), Clemson University, Clemson SC 29634.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Anker