[21p-P10-1~12] 3.12 Nanoscale optical science and near-field optics

[21p-P10-4] Interference-based Plasmonic Coloring of Gold Nanoparticle Dimers and Observation of Rotational Diffusion Dynamics

〇Hiroki Endo¹, Bokusui Nakayama¹, Keiko Esashika¹, Yuki Hiruta¹, Toshiharu Saiki¹ (1.Keio Univ.)

Keywords:plasmonics, sensing, nanoparticle

We report the results of using a gold nanoparticle dimer with large optical anisotropy to demonstrate the color change associated with rotational motion and applying it to the observation of rotational diffusion motion. The color produced by the interference between the scattered light of the particle and the reflected light from the substrate is determined by two parameters, the distance d from the substrate and the rotation angle θ between the long axis of the gold particle and the substrate. This allows us to estimate the diffusional motion of the observed particles and actually identify the rotational diffusional motion of the particles by the color change.