Three Dimensional Orientational Imaging of Nanoparticles with Darkfield Microscopy

Abstract

The complete three-dimensional orientations of single gold nanorods (AuNR) were successfully resolved by using a standard optical darkfield microscope through deciphering the field distribution pattern in the slightly defocused darkfield images. The resulting images depend on the aspect ratio of the AuNR, the numerical aperture of the objective, the defocusing distance, and the polarization direction of the incident radiation. Interpretation of the observed images is facilitated by comparing them with a series of simulated images with different parameters. The experimental data matched well with the simulated results, and the reliability of this technique was further verified with polarization modulation experiments. Since deconvolution can be performed off-line after the images are recorded, this approach essentially allows video-rate data acquisition. The convenient, reliable and rapid angle-resolving capability should enable broad applications in imaging studies in many scientific fields.

Frozen Translational and Rotational Motion of Human Immunodeficiency Virus Transacting Activator of Transcription Peptide-Modified Nanocargo on Neutral Lipid Bilayer

“…37 In this work, we derived the rotational dynamics of individual gold nanorods through selectively exciting the nanorod in the longitudinal mode. The angle-dependent polarized scattering signal was then discriminated by placing a half-wave plate in the emission light path.…”

Selectively Imaging Single Gold Nanorods by Polarized Light Microscopy with Low Background

“…2d. Also, a very small number of the emerged spots appear red under DFM since the long axis of GNRs is along the polarization direction of polarizer or analyzer [33]. Thus, PLM has some limitations in observing immobile GNRs on the surfaces but should be very useful for investigating moving GNRs under various environments.…”

Platinum-coated Core-Shell Gold Nanorods as Multifunctional Orientation Sensors in Differential Interference Contrast Microscopy

“…Furthermore, characteristic scattering image patterns have been employed to decipher 3D orientation of single AuNRs without angular degeneracy. 4,[18][19][20][21][22] Despite recent advances in single particle rotational tracking techniques, there have been very limited studies on the development of new optical orientation probes that can provide higher sensitivity, multi-functionality, etc.…”