|Science of Rock 'n' Roll: Deciphering Motions in Live Cells|
: 187 : 2017.03.22 10:24
|일시 : 2017.03.22 17:00|
|소속 : 울산대학교 화학과|
|발표자 : 하지원|
|장소 : AS510|
Plasmonic gold nanorods (AuNRs) have been used as orientation probes in optical imaging because of their shape-induced anisotropic optical properties. However, current optical imaging techniques lack the capability to decipher the full three-dimensional (3D) orientation of an in-focus gold nanorod in the four quadrants of the Cartesian plane. Resolving the orientation angles and determining the accurate rotational modes of the gold nanorod are critical in biological observations because the chirality of biological macromolecules and their assemblies, for example right- or left-handed helices, is fundamental in biology.
In this talk, a novel optical rotational tracking method with the capability of full-space orientation resolvability for individual in-focus nanoprobes without sacrificing spatial and temporal resolution is demonstrated to overcome the limitations of current polarization anisotropy techniques. More specifically, we overcome this limitation by combining differential interference contrast (DIC) microscopy image pattern recognition with DIC polarization anisotropy analysis to resolve the exact azimuthal angles (from 0° to 360°) as well as the polar angles of tilted AuNRs that are positioned in the focal plane of the objective lens. The rotational direction of individual in-focus AuNRs can thus be tracked dynamically. The applicability and usefulness of this method toward in vivo studies in biological systems was also verified by the precise tracking of 3D orientation angles of AuNRs rotating on live cell membranes. Deciphering the full 3D orientation information of the probe or nanocargo in a dynamic fashion will shed new light on physical and biological processes with characteristic rotational motions, such as the detailed working mechanisms of molecular nanomachines and relevant assisting proteins during the internalization of functional drug delivery vectors.