title: Active Nanorheology with Plasmonics.
abstract: Nanoplasmonic systems are valued for their strong optical response and their small size. Most plasmonic sensors and systems to date have been rigid and passive. However, rendering these structures dynamic opens new possibilities for applications. Here we demonstrate that dynamic plasmonic nanoparticles can be used as mechanical sensors to selectively probe the rheological properties of a fluid in situ at the nanoscale and in microscopic volumes. We fabricate chiral magneto-plasmonic nanocolloids that can be actuated by an external magnetic field, which in turn allows for the direct and fast modulation of their distinct optical response. The method is robust and allows nanorheological measurements with a mechanical sensitivity of ∼0.1 cP, even in strongly absorbing fluids with an optical density of up to OD ∼ 3 (∼0.1% light transmittance) and in the presence of scatterers (e.g., 50% v/v red blood cells).
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Hyeon-Ho
authors.initials: HH
authors.lastname: Jeong
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Mark
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|UCL Institute for Materials Discovery and Department of Chemistry, University College London , Christopher Ingold Building, 20 Gordon Street, London WC1H 0AJ, United Kingdom.
authors.forename: Tung-Chun
authors.initials: TC
authors.lastname: Lee
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Institute for Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569 Stuttgart, Germany.
authors.forename: Mariana
authors.initials: M
authors.lastname: Alarcón-Correa
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Institute for Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569 Stuttgart, Germany.
authors.forename: Sahand
authors.initials: S
authors.lastname: Eslami
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015 Lausanne, Switzerland.
authors.forename: Tian
authors.initials: T
authors.lastname: Qiu
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Department of Physics and Astronomy, Northern Arizona University , S. San Francisco Street, Flagstaff, Arizona 86011, United States.
authors.forename: John G
authors.initials: JG
authors.lastname: Gibbs
authors.affiliation: Max Planck Institute for Intelligent Systems , Heisenbergstrasse 3, 70569 Stuttgart, Germany.|Institute for Physical Chemistry, University of Stuttgart , Pfaffenwaldring 55, 70569 Stuttgart, Germany.
authors.forename: Peer
authors.initials: P
authors.lastname: Fischer
keywords: Magneto-plasmonics; chiral plasmonics; chiroptical switch; nanorheology