title: Scattering based hyperspectral imaging of plasmonic nanoplate clusters towards biomedical applications.
abstract: A new optical scattering contrast-agent based on polymer-nanoparticle encapsulated silver nanoplates (PESNs) is presented. Silver nanoplates were chosen due to the flexibility of tuning their plasmon frequencies. The polymer coating preserves their physical and optical properties and confers other advantages such as controlled contrast agent delivery. Finite difference time domain (FDTD) simulations model the interaction of light with the nanoplates in different orientations in the cluster. Hyperspectral dark field microscopy (HYDFM) observes the scattering spectra of the PESNs. An unsupervised sequential maximum angle convex cone (SMACC) image analysis resolves spectral endmembers corresponding to different stacking orientations of the nanoplates. The orientation-dependent endmembers qualitatively agree with the FDTD results. For contrast enhancement, the uptake and spatial distribution of PESNs are demonstrated by an HYDFM study of single melanoma cells to result in an enhanced contrast of up to 400%. A supervised spatial mapping of the endmembers obtained by the unsupervised SMACC algorithm reveals spatial distributions of PESNs with various clustering orientations of encapsulated nanoplates. Our study demonstrates tunability in plasmonics properties in clustered metal nanoparticles and its utility for the development of scatter-based imaging contrast agents for a broad range of applications, including studies of single cells and other biomedical systems.
authors.affiliation: Quantum Electronics and Photonics Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA.|Department of Chemistry and Biophysics, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, USA.
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Ray
authors.affiliation: Department of Chemistry and Biophysics, University of Michigan, 930 N. University Ave, Ann Arbor, MI, 48109, USA.
authors.forename: Raoul
authors.initials: R
authors.lastname: Kopelman
authors.affiliation: Quantum Electronics and Photonics Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA.
authors.forename: Bonghwan
authors.initials: B
authors.lastname: Chon
authors.affiliation: Quantum Electronics and Photonics Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Briggman
authors.affiliation: Quantum Electronics and Photonics Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO, 80305, USA. jch@nist.gov.
authors.forename: Jeeseong
authors.initials: J
authors.lastname: Hwang
mesh_terms: D008027:Light; D053768:Metal Nanoparticles; D008853:Microscopy; D011108:Polymers; D012834:Silver
chemical_list: D011108:Polymers; D012834:Silver
keywords: FDTD simulation; cancer cells; hyperspectral dark field imaging; nanoplate clusters