Analytical Sciences

Abstract − Analytical Sciences, 35(11), 1237 (2019).

Single-particle Correlation Study: Polarization-dependent Differential Interference Contrast Imaging of Two-dimensional Gold Nanoplates
Junho LEE and Ji Won HA
Advanced Nano Bio Imaging and Spectroscopy Laboratory, Department of Chemistry, University of Ulsan, 93 Daehak-Ro, Nam-Gu, Ulsan 44610, Republic of Korea
Questions surrounding the optical properties of two-dimensional (2D) triangular single gold nanoplates (AuNPs) remain largely unanswered. Herein, a scanning-electron microscopy-correlated single-particle study was conducted to identify polarization-dependent optical properties of AuNPs under dark-field (DF) and differential interference contrast (DIC) microscopy. AuNPs with an aspect ratio of ∼3 showed a single broad DF scattering spectrum without separation of the two dipole and quadrupole resonance modes present in 2D AuNPs. Polarization-sensitive interference properties of the individual AuNPs were revealed through periodic changes in the intensities and types of DIC images obtained. A dipole resonance mode was found to mainly contribute to the polarization-sensitive interference properties of AuNPs. Furthermore, DIC polarization anisotropy allowed us to track the real-time orientation of a dipole resonance mode of a AuNP rotating on a live cell membrane.