Differential interference contrast microscopy imaging of single gold nanospheres beyond the quasi-static limit

Abstract

Herein, we employed single particle dark-field (DF) and differential interference contrast (DIC) microscopy to investigate the particle size dependency for large gold nanospheres (AuNSs) with average diameters of 100nm, 300nm, and 400nm. Higher order plasmon resonances were observed in the single particle scattering spectra of large AuNSs (300nm and 400nm). Furthermore, the DF and DIC intensities were linearly increased with increasing the particle size from 100nm to 400nm. Therefore, the results provide useful experimental information of how the scattering and interference properties of single AuNSs are influenced by the particle size.