Optical Properties of Metacrystals Based on Protein Nanocages

Advanced Functional Materials, vol. 33

Abstract

Abstract The optical properties of 3D metacrystals made of gold nanoparticles in protein nanocages are studied. These metacrystals have sizes of tens of micrometers and are of high structural and optical quality. Through microspectroscopy measurements and model calculations it is demonstrated that the metacrystals show plasmonic absorption in the green wavelength range and are largely transparent in the red and infrared ranges. By using empty nanocages as placeholders in the metacrystal lattice, it is possible to control how strongly the metamaterial absorbs. Measurements on a pyramidal metacrystal show that it deflects visible light. The deflection shows evidence for anomalous refraction at short wavelengths and normal refraction at long wavelengths. The refractive dispersion is ascribed to the optical dispersion relation of the plasmonic metamaterial.

Authors 8

1. Niklas O. Junker Aachen Institute of Physics (IA)

   RWTH Aachen University

   Affiliation as printed

   Institute of Physics (1A) RWTH Aachen University Sommerfeldstraße 14 52074 Aachen Germany

2. Anja Lindenau Aachen Institute of Physics (IA)

   RWTH Aachen University

   Affiliation as printed

   Institute of Physics (1A) RWTH Aachen University Sommerfeldstraße 14 52074 Aachen Germany

3. Michael Rütten

   Universität Hamburg

   Affiliation as printed

   Institute of Physical Chemistry Department of Chemistry Universität Hamburg Grindelallee 117 20146 Hamburg Germany

4. Marcel Lach

   Universität Hamburg

   Affiliation as printed

   Institute of Physical Chemistry Department of Chemistry Universität Hamburg Grindelallee 117 20146 Hamburg Germany

5. Alexander Nedilko Aachen Institute of Physics (IA)

   RWTH Aachen University

   Affiliation as printed

   Institute of Physics (1A) RWTH Aachen University Sommerfeldstraße 14 52074 Aachen Germany

6. Dmitry N. Chigrin Aachen Institute of Physics (IA)

   RWTH Aachen University · DWI – Leibniz Institute for Interactive Materials

   Affiliation as printed

   DWI – Leibniz‐Institut für Interaktive Materialien e.V. Forckenbeckstraße 50 52074 Aachen Germany

   Institute of Physics (1A) RWTH Aachen University Sommerfeldstraße 14 52074 Aachen Germany

7. G. von Plessen corresponding Aachen Institute of Physics (IA)

   RWTH Aachen University

   Affiliation as printed

   Institute of Physics (1A) RWTH Aachen University Sommerfeldstraße 14 52074 Aachen Germany

8. Tobias Beck corresponding

   Universität Hamburg · Hamburg Centre for Ultrafast Imaging

   Affiliation as printed

   Hamburg Centre for Ultrafast Imaging Universität Hamburg Luruper Chaussee 149 22761 Hamburg Germany

   Institute of Physical Chemistry Department of Chemistry Universität Hamburg Grindelallee 117 20146 Hamburg Germany