title: 3-Dimensional Tracking of Non-blinking 'Giant' Quantum Dots in Live Cells.
abstract: While semiconductor quantum dots (QDs) have been used successfully in numerous single particle tracking (SPT) studies due to their high photoluminescence efficiency, photostability, and broad palette of emission colors, conventional QDs exhibit fluorescence intermittency or 'blinking,' which causes ambiguity in particle trajectory analysis and limits tracking duration. Here, non-blinking 'giant' quantum dots (gQDs) are exploited to study IgE-FcεRI receptor dynamics in live cells using a confocal-based 3D SPT microscope. There is a 7-fold increase in the probability of observing IgE-FcεRI for longer than 1 min using the gQDs compared to commercially available QDs. A time-gated photon-pair correlation analysis is implemented to verify that selected SPT trajectories are definitively from individual gQDs and not aggregates. The increase in tracking duration for the gQDs allows the observation of multiple changes in diffusion rates of individual IgE-FcεRI receptors occurring on long (>1 min) time scales, which are quantified using a time-dependent diffusion coefficient and hidden Markov modeling. Non-blinking gQDs should become an important tool in future live cell 2D and 3D SPT studies, especially in cases where changes in cellular dynamics are occurring on the time scale of several minutes.
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Aaron M
authors: AM
authors: Keller
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Yagnaseni
authors: Y
authors: Ghosh
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Matthew S
authors: MS
authors: DeVore
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Mary E
authors: ME
authors: Phipps
authors: Optical Sciences Division, Code 5600, US Naval Research Laboratory, Washington, D.C. 20375, USA.
authors: Michael H
authors: MH
authors: Stewart
authors: Department of Pathology and Cancer Research and Treatment Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 97131, USA.
authors: Bridget S
authors: BS
authors: Wilson
authors: Department of Pathology and Cancer Research and Treatment Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 97131, USA.
authors: Diane S
authors: DS
authors: Lidke
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: Jennifer A
authors: JA
authors: Hollingsworth
authors: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors: James H
authors: JH
authors: Werner