Stable Small Quantum Dots for Synaptic Receptor Tracking on Live Neurons

Cai, En; Ge, Pinghua; Lee, Sang Hak; Jeyifous, Okunola; Wang, Yong; Liu, Yanxin; Wilson, Katie; Lim, Sung Jun; Baird, Michelle A.; Stone, John E.; Lee, Kwan Young; Davidson, Michael W.; Chung, Hee Jung; Schulten, Klaus; Smith, Andrew; Green, William N.; Selvin, Paul R.

doi:10.1002/anie.201405735

Cited by 67 publications

(89 citation statements)

References 37 publications

(41 reference statements)

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“…Owing to the rather week luminescence modulation we tentatively attributed this phenomenon to a radiative energy transfer mechanism between the luminophore and the spin crossover complex resulting from the spectral overlap between the luminescence emission and the absorption of the complex in the LS state. The photo-thermal degradation of the luminophore was also observed and further work should focus on solving this issue by appropriate surface modification (encapsulation) of the CdTe nanocrystals [36]. The most interesting perspective of the present work will be the detailed investigation of the relationship between the spectral overlap and the luminescence modulation.…”

Section: Discussionmentioning

confidence: 85%

CdTe Quantum Dot Fluorescence Modulation by Spin Crossover

et al. 2016

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Nanocomposite materials containing Cadmium Telluride (CdTe) nanocrystals and [Fe(H-trz) 2 (trz)]BF 4 nanoparticles were synthesized and investigated for the coupling between their photoluminescent and spin crossover properties. The bright CdTe emission around 550 nm was found to decrease reversibly when switching the ferrous complex from the high spin (HS) to the low spin (LS) state, which was attributed to the spectral overlap of the luminescence with the absorption of the complex in the latter electronic configuration. A significant irreversible change of the luminescence signal (photobleaching) was also observed both in emission intensity and lifetime measurements.

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Section: Discussionmentioning

confidence: 85%

CdTe Quantum Dot Fluorescence Modulation by Spin Crossover

et al. 2016

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“…Artifacts due to steric hindrance are particularly evident in crowded media of cells and tissues, which have characteristic size thresholds above which large QDs (~15-35 nm) cannot be used to accurately measure biomolecular targets. One of these is the synaptic cell-cell junction between connected neurons, a 20-30 nm region that large QDs cannot access [165]. Large QDs are also immobile in the cellular cytoplasm [166, 167], cannot efficiently penetrate through tissue matrix [168], and cannot clear from mammalian vascular circulation through renal filtration [168-170].…”

Section: Surface Engineering For Biomedical Applicationsmentioning

confidence: 99%

Quantum dot surface engineering: Toward inert fluorophores with compact size and bright, stable emission

Lim

Schleife

et al. 2016

Coordination Chemistry Reviews

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109

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The surfaces of colloidal nanocrystals are complex interfaces between solid crystals, coordinating ligands, and liquid solutions. For fluorescent quantum dots, the properties of the surface vastly influence the efficiency of light emission, stability, and physical interactions, and thus determine their sensitivity and specificity when they are used to detect and image biological molecules. But after more than 30 years of study, the surfaces of quantum dots remain poorly understood and continue to be an important subject of both experimental and theoretical research. In this article, we review the physics and chemistry of quantum dot surfaces and describe approaches to engineer optimal fluorescent probes for applications in biomolecular imaging and sensing. We describe the structure and electronic properties of crystalline facets, the chemistry of ligand coordination, and the impact of ligands on optical properties. We further describe recent advances in compact coatings that have significantly improved their properties by providing small hydrodynamic size, high stability and fluorescence efficiency, and minimal nonspecific interactions with cells and biological molecules. While major progress has been made in both basic and applied research, many questions remain in the chemistry and physics of quantum dot surfaces that have hindered key breakthroughs to fully optimize their properties.

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“…EGFRs tagged with a 40 nm gold particle exhibit a diffusivity (~3 Â 10 À3 mm 2 /s) lower than that of EGFRs tagged with a commercial quantum dot (~0.04 mm 2 /s) (50) or fused with an EGFP (~0.2 mm 2 /s) (106). Although large nanoparticle labels have also been used for high-resolution tracking of a wide range of membrane proteins (such as glycine receptors (107), GPI anchor proteins (17), a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-D-aspartate receptors (108), integrins (109), and cystic fibrosis transmembrane conductance regulator channel proteins (110,111)), smaller particle labels (diameter < 10 nm) are recently developed and tested for SPT in a confined space (such as synaptic receptors in synaptic cleft (27)), providing less steric hindrance and reduced cross-linking. To completely eliminate cross-linking, we are currently developing monovalent EGFR labeling techniques based on site-specific biotinylation of membrane receptors (113), monovalent streptavidin (114,115), and monovalent nanoparticles (116).…”

Section: Trade-offs In Temporal Resolution and Probe Sizementioning

confidence: 99%

“…Whereas SPT has made important discoveries that change our view of plasma membrane organization (17,19) and molecular motor dynamics (20), the use of SPT in monitoring ''intracellular'' processes is rather limited because of the lack of three-dimensional (3D) tracking capacity that can follow a single particle inside a live cell for a long period of time. In the past decade, new SPT techniques have been developed to visualize molecular motion in the 3D space (termed 3D-SPT), including multiple imaging planes (21,22), orbital tracking (23)(24)(25), point spread function engineering (26,27), and confocal tracking (28,29). Although allowing for direct observation of transport processes from membrane to cytoplasm, current 3D-SPT methods often suffer from shallow imaging depth (because of the use of one-photon excitation) and limited z-tracking range (e.g., astigmatismbased, nonfeedback tracking systems (27)), which prevent these methods from tracking single molecules inside multicellular models such as spheroids (see our review in (8)).…”

Section: Introductionmentioning

confidence: 99%

Segmentation of 3D Trajectories Acquired by TSUNAMI Microscope: An Application to EGFR Trafficking

Liu

Perillo

Liu

et al. 2016

Biophysical Journal

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Whereas important discoveries made by single-particle tracking have changed our view of the plasma membrane organization and motor protein dynamics in the past three decades, experimental studies of intracellular processes using singleparticle tracking are rather scarce because of the lack of three-dimensional (3D) tracking capacity. In this study we use a newly developed 3D single-particle tracking method termed TSUNAMI (Tracking of Single particles Using Nonlinear And Multiplexed Illumination) to investigate epidermal growth factor receptor (EGFR) trafficking dynamics in live cells at 16/43 nm (xy/z) spatial resolution, with track duration ranging from 2 to 10 min and vertical tracking depth up to tens of microns. To analyze the long 3D trajectories generated by the TSUNAMI microscope, we developed a trajectory analysis algorithm, which reaches 81% segment classification accuracy in control experiments (termed simulated movement experiments). When analyzing 95 EGF-stimulated EGFR trajectories acquired in live skin cancer cells, we find that these trajectories can be separated into three groups-immobilization (24.2%), membrane diffusion only (51.6%), and transport from membrane to cytoplasm (24.2%). When EGFRs are membrane-bound, they show an interchange of Brownian diffusion and confined diffusion. When EGFRs are internalized, transitions from confined diffusion to directed diffusion and from directed diffusion back to confined diffusion are clearly seen. This observation agrees well with the model of clathrin-mediated endocytosis.

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Stable Small Quantum Dots for Synaptic Receptor Tracking on Live Neurons

Cited by 67 publications

References 37 publications

CdTe Quantum Dot Fluorescence Modulation by Spin Crossover

CdTe Quantum Dot Fluorescence Modulation by Spin Crossover

Quantum dot surface engineering: Toward inert fluorophores with compact size and bright, stable emission

Segmentation of 3D Trajectories Acquired by TSUNAMI Microscope: An Application to EGFR Trafficking

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