51
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DNA-Protein Interactions Studied Directly Using Single Molecule Fluorescence Imaging of Quantum Dot Tagged Proteins Moving on DNA Tightropes. Methods Mol Biol 2016; 1431:141-50. [PMID: 27283307 DOI: 10.1007/978-1-4939-3631-1_11] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many protein interactions with DNA require specific sequences; however, how these sequences are located remains uncertain. DNA normally appears bundled in solution but, to study DNA-protein interactions, the DNA needs to be elongated. Using fluidics single DNA strands can be efficiently and rapidly elongated between beads immobilized on a microscope slide surface. Such "DNA tightropes" offer a valuable method to study protein search mechanisms. Real-time fluorescence imaging of these interactions provides quantitative descriptions of search mechanism at the single molecule level. In our lab, we use this method to study the complex process of nucleotide excision DNA repair to determine mechanisms of damage detection, lesion removal, and DNA excision.
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52
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Non-blinking (Zn)CuInS/ZnS Quantum Dots Prepared by In Situ Interfacial Alloying Approach. Sci Rep 2015; 5:15227. [PMID: 26458511 PMCID: PMC4602315 DOI: 10.1038/srep15227] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 09/15/2015] [Indexed: 11/09/2022] Open
Abstract
Semiconductor quantum dots (QDs) are very important optical nanomaterials with a wide range of potential applications. However, blinking behavior of single QD is an intrinsic drawback for some biological and photoelectric applications based on single-particle emission. Herein we present a rational strategy for fabrication of non-blinking (Zn)CuInS/ZnS QDs in organic phase through in situ interfacial alloying approach. This new strategy includes three steps: synthesis of CuInS QDs, eliminating the interior traps of QDs by forming graded (Zn)CuInS alloyed QDs, modifying the surface traps of QDs by introducing ZnS shells onto (Zn)CuInS QDs using alkylthiols as sulfur source and surface ligands. The suppressed blinking mechanism was mainly attributed to modifying QDs traps from interior to exterior via a step-by-step modification. Non-blinking QDs show high quantum yield, symmetric emission spectra and excellent crystallinity, and will enable applications from biology to optoelectronics that were previously hindered by blinking behavior of traditional QDs.
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53
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Chen GH, Yeh CW, Yeh MH, Ho SJ, Chen HS. Wide gamut white light emitting diodes using quantum dot-silicone film protected by an atomic layer deposited TiO2 barrier. Chem Commun (Camb) 2015; 51:14750-3. [PMID: 26295071 DOI: 10.1039/c5cc05299h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Wide gamut light emitting diodes using quantum dot-silicone film protected by atomic layer deposited TiO2 film were demonstrated. The core/shell QDs with multi-emission peaks were synthesised by a one-pot approach, in which the emission wavelength and colour composition were in situ adjusted during the synthetic process.
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Affiliation(s)
- Guan-Hong Chen
- Department of Materials Science & Engineering, National Tsing Hua University, No. 101, Sec. 2, Guangfu Rd., Hsinchu City 300, Taiwan.
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54
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Nanayakkara SU, van de Lagemaat J, Luther JM. Scanning Probe Characterization of Heterostructured Colloidal Nanomaterials. Chem Rev 2015. [PMID: 26196958 DOI: 10.1021/cr500280t] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Sanjini U. Nanayakkara
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Jao van de Lagemaat
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Joseph M. Luther
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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55
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Abstract
Quantum dots (QDs) are nanoparticles with fluorescent properties that offer advantages over organic fluorophores. As a result, QDs have found wide application in biological imaging. In this introduction we discuss the approaches for using QDs for labeling and imaging individual cells and cellular processes in live cells both in vivo and in culture.
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56
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Ray K, Badugu R, Lakowicz JR. Bloch Surface Wave-Coupled Emission from Quantum Dots by Ensemble and Single Molecule Spectroscopy. RSC Adv 2015; 5:54403-54411. [PMID: 26523227 PMCID: PMC4624411 DOI: 10.1039/c5ra03413b] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report the spectral properties and spatial distribution of quantum dot (QD575 ) emission on a one-dimensional photonic crystal (1DPC). Our 1DPC substrate consists of multiple layers of dielectrics with a photonic band gap (PBG) near the QD575 emission maximum. The 1DPC was designed to display a surface-trapped electromagnetic state known as a Bloch surface wave (BSW) at the 1DPC-air (sample) interface. Ensemble angle-dependent emission intensities revealed a sharp angular emission peak near 41° from the normal which is consistent with the BSW resonance at 575 nm. We further examined the emission from single QDs on the 1DPC. A notable increase in fluorescence intensity from QD575 particles was observed on BSW substrate compared to the glass substrate from the scanning confocal fluorescence images and from the intensity-time trajectories of single QD575 particles. The intensity-decays showed substantially faster decay (4-fold decrease in emission lifetime) from the single QD575 particles on 1DPC substrate (∼4.8 nsec) as compared to the glass substrate (∼18 nsec). We observed the spectral characteristics of the individual QD575 particles on 1DPC and glass substrates, by recording the single particle emission spectra through the 1DPC. The emission spectra of the single QD575 particles are similar (with emission maxima around 575 nm) on both substrates except a substantial increase in intensity (over 10-fold) on the BSW substrate. Our results demonstrate that quantum dots can interact with Bloch Surface Waves (BSW) on a 1DPC. To the best of our knowledge, this is the first report on the single particle fluorescence studies on 1DPC substrate. The 10-fold increase in intensity in combination with 4-fold reduction in emission lifetime suggest 1DPCs with BSW modes have potential use in sensing and single molecule spectroscopy.
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Affiliation(s)
- Krishanu Ray
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, United States
| | - Ramachandram Badugu
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, United States
| | - Joseph R. Lakowicz
- Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, United States
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57
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Whitham PJ, Knowles KE, Reid PJ, Gamelin DR. Photoluminescence Blinking and Reversible Electron Trapping in Copper-Doped CdSe Nanocrystals. NANO LETTERS 2015; 15:4045-51. [PMID: 26007328 DOI: 10.1021/acs.nanolett.5b01046] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Single-particle photoluminescence blinking is observed in the copper-centered deep-trap luminescence of copper-doped CdSe (Cu(+):CdSe) nanocrystals. Blinking dynamics for Cu(+):CdSe and undoped CdSe nanocrystals are analyzed to identify the effect of Cu(+), which selectively traps photogenerated holes. Analysis of the blinking data reveals that the Cu(+):CdSe and CdSe nanocrystal "off"-state dynamics are statistically identical, but the Cu(+):CdSe nanocrystal "on" state is shorter lived. Additionally, a new and pronounced temperature-dependent delayed luminescence is observed in the Cu(+):CdSe nanocrystals that persists long beyond the radiative lifetime of the luminescent excited state. This delayed luminescence is analogous to the well-known donor-acceptor pair luminescence of bulk copper-doped phosphors and is interpreted as revealing metastable charge-separated excited states formed by reversible electron trapping at the nanocrystal surfaces. A mechanistic link between this delayed luminescence and the luminescence blinking is proposed. Collectively, these data suggest that electron (rather than hole) trapping/detrapping is responsible for photoluminescence intermittency in these nanocrystals.
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Affiliation(s)
- Patrick J Whitham
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Kathryn E Knowles
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Philip J Reid
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
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58
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Nasilowski M, Spinicelli P, Patriarche G, Dubertret B. Gradient CdSe/CdS Quantum Dots with Room Temperature Biexciton Unity Quantum Yield. NANO LETTERS 2015; 15:3953-8. [PMID: 25990468 DOI: 10.1021/acs.nanolett.5b00838] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Auger recombination is a major limitation for the fluorescent emission of quantum dots (QDs). It is the main source of QDs fluorescence blinking at the single-particle level. At high-power excitation, when several charge carriers are formed inside a QD, Auger becomes more efficient and severely decreases the quantum yield (QY) of multiexcitons. This limits the efficiency and the use of colloidal QDs in applications where intense light output is required. Here, we present a new generation of thick-shell CdSe/CdS QDs with dimensions >40 nm and a composition gradient between the core and the shell that exhibits 100% QY for the emission of both the monoexciton and the biexciton in air and at room temperature for all the QDs we have observed. The fluorescence emission of these QDs is perfectly Poissonian at the single-particle level at different excitation levels and temperatures, from 30 to 300 K. In these QDs, the emission of high-order (>2) multiexcitons is quite efficient, and we observe white light emission at the single-QD level when high excitation power is used. These gradient thick shell QDs confirm the suppression of Auger recombination in gradient core/shell structures and help further establish the colloidal QDs with a gradient shell as a very stable source of light even under high excitation.
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Affiliation(s)
- Michel Nasilowski
- †Laboratoire de Physique et d'Etude des Matériaux (LPEM), PSL Research University, ESPCI-ParisTech, 10 rue Vauquelin, F-75231 Paris Cedex 5, France
- ‡UMR 8213, CNRS, F-75005 Paris, France
- §UPMC Univ Paris 06, Sorbonne Universités, F-75005 Paris, France
| | - Piernicola Spinicelli
- †Laboratoire de Physique et d'Etude des Matériaux (LPEM), PSL Research University, ESPCI-ParisTech, 10 rue Vauquelin, F-75231 Paris Cedex 5, France
- ‡UMR 8213, CNRS, F-75005 Paris, France
- §UPMC Univ Paris 06, Sorbonne Universités, F-75005 Paris, France
| | - Gilles Patriarche
- ⊥Laboratoire Photonique et Nanostructures, CNRS, 91460 Marcoussis, France
| | - Benoît Dubertret
- †Laboratoire de Physique et d'Etude des Matériaux (LPEM), PSL Research University, ESPCI-ParisTech, 10 rue Vauquelin, F-75231 Paris Cedex 5, France
- ‡UMR 8213, CNRS, F-75005 Paris, France
- §UPMC Univ Paris 06, Sorbonne Universités, F-75005 Paris, France
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59
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Hanne J, Falk HJ, Görlitz F, Hoyer P, Engelhardt J, Sahl SJ, Hell SW. STED nanoscopy with fluorescent quantum dots. Nat Commun 2015; 6:7127. [PMID: 25980788 PMCID: PMC4479004 DOI: 10.1038/ncomms8127] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Accepted: 04/02/2015] [Indexed: 11/14/2022] Open
Abstract
The widely popular class of quantum-dot molecular labels could so far not be utilized as standard fluorescent probes in STED (stimulated emission depletion) nanoscopy. This is because broad quantum-dot excitation spectra extend deeply into the spectral bands used for STED, thus compromising the transient fluorescence silencing required for attaining super-resolution. Here we report the discovery that STED nanoscopy of several red-emitting commercially available quantum dots is in fact successfully realized by the increasingly popular 775 nm STED laser light. A resolution of presently ∼ 50 nm is demonstrated for single quantum dots, and sub-diffraction resolution is further shown for imaging of quantum-dot-labelled vimentin filaments in fibroblasts. The high quantum-dot photostability enables repeated STED recordings with >1,000 frames. In addition, we have evidence that the tendency of quantum-dot labels to blink is largely suppressed by combined action of excitation and STED beams. Quantum-dot STED significantly expands the realm of application of STED nanoscopy, and, given the high stability of these probes, holds promise for extended time-lapse imaging.
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Affiliation(s)
- Janina Hanne
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
| | - Henning J. Falk
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
| | - Frederik Görlitz
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
| | - Patrick Hoyer
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
| | - Johann Engelhardt
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
| | - Steffen J. Sahl
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
| | - Stefan W. Hell
- German Cancer Research Center (DKFZ), Optical Nanoscopy Division, Im Neuenheimer Feld 280, Heidelberg 69120, Germany
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen 37077, Germany
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60
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Abstract
Luminescence blinking is an inherent feature of optical emission from individual fluorescent molecules and quantum dots. There have been intense efforts, although not with complete resolution, toward the understanding of the mechanistic origin of blinking and also its mitigation in quantum dots. As an advance in our microscopic view of blinking, we show that the luminescence blinking of a quantum dot becomes unusually heavy in the temporal vicinity of a reactive transformation. This stage of heavy blinking is a result of defects/dopants formed within the quantum dot on its path to conversion. The evolution of blinking behavior along the reaction path allows us to measure the lifetime of the critical dopant-related intermediate in the reaction. This work establishes luminescence blinking as a single-nanocrystal level probe of catalytic, photocatalytic, and electrochemical events occurring in the solid-state or on semiconductor surfaces.
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Affiliation(s)
- Aaron L Routzahn
- †Department of Chemistry, ‡Department of Physics, and §Materials Research Lab, University of Illinois, Urbana-Champaign, Illinois 61801, United States
| | - Prashant K Jain
- †Department of Chemistry, ‡Department of Physics, and §Materials Research Lab, University of Illinois, Urbana-Champaign, Illinois 61801, United States
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61
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Minowa Y, Kawai R, Ashida M. Optical levitation of a microdroplet containing a single quantum dot. OPTICS LETTERS 2015; 40:906-909. [PMID: 25768143 DOI: 10.1364/ol.40.000906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate the optical levitation or trapping in helium gas of a single quantum dot (QD) within a liquid droplet. Bright single photon emission from the levitated QD in the droplet was observed for more than 200 s. The observed photon count rates are consistent with the value theoretically estimated from the two-photon-action cross section. This Letter presents the realization of an optically levitated solid-state quantum emitter.
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62
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Hu F, Cao Z, Zhang C, Wang X, Xiao M. Defect-induced photoluminescence blinking of single epitaxial InGaAs quantum dots. Sci Rep 2015; 5:8898. [PMID: 25754220 PMCID: PMC4354043 DOI: 10.1038/srep08898] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/06/2015] [Indexed: 11/09/2022] Open
Abstract
Here we report two types of defect-induced photoluminescence (PL) blinking behaviors observed in single epitaxial InGaAs quantum dots (QDs). In the first type of PL blinking, the "off" period is caused by the trapping of hot electrons from the higher-lying excited state (absorption state) to the defect site so that its PL rise lifetime is shorter than that of the "on" period. For the "off" period in the second type of PL blinking, the electrons relax from the first excited state (emission state) into the defect site, leading to a shortened PL decay lifetime compared to that of the "on" period. This defect-induced exciton quenching in epitaxial QDs, previously demonstrated also in colloidal nanocrystals, confirms that these two important semiconductor nanostructures could share the same PL blinking mechanism.
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Affiliation(s)
- Fengrui Hu
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Zengle Cao
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Chunfeng Zhang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Xiaoyong Wang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Min Xiao
- 1] National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China [2] Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA
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63
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Yamashita SI, Hamada M, Nakanishi S, Saito H, Nosaka Y, Wakida SI, Biju V. Auger Ionization Beats Photo-Oxidation of Semiconductor Quantum Dots: Extended Stability of Single-Molecule Photoluminescence. Angew Chem Int Ed Engl 2015; 54:3892-6. [DOI: 10.1002/anie.201501131] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Indexed: 12/31/2022]
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64
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Yamashita SI, Hamada M, Nakanishi S, Saito H, Nosaka Y, Wakida SI, Biju V. Auger Ionization Beats Photo-Oxidation of Semiconductor Quantum Dots: Extended Stability of Single-Molecule Photoluminescence. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501131] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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65
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Synthesis, characterization and biomedical application of multifunctional luminomagnetic core–shell nanoparticles. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 46:32-40. [DOI: 10.1016/j.msec.2014.10.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/08/2014] [Accepted: 10/02/2014] [Indexed: 01/10/2023]
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66
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Surface functionalization of quantum dots for biological applications. Adv Colloid Interface Sci 2015; 215:28-45. [PMID: 25467038 DOI: 10.1016/j.cis.2014.11.004] [Citation(s) in RCA: 128] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/25/2014] [Accepted: 11/10/2014] [Indexed: 01/17/2023]
Abstract
Quantum dots are a group of inorganic nanomaterials exhibiting exceptional optical and electronic properties which impart distinct advantages over traditional fluorescent organic dyes in terms of tunable broad excitation and narrow emission spectra, signal brightness, high quantum yield and photo-stability. Aqueous solubility and surface functionalization are the most common problems for QDs employed in biological research. This review addresses the recent research progress made to improve aqueous solubility, functionalization of biomolecules to QD surface and the poorly understood chemistry involved in the steps of bio-functionalization of such nanoparticles.
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67
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Wegner KD, Hildebrandt N. Quantum dots: bright and versatile in vitro and in vivo fluorescence imaging biosensors. Chem Soc Rev 2015; 44:4792-4834. [DOI: 10.1039/c4cs00532e] [Citation(s) in RCA: 550] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Colourful cells and tissues: semiconductor quantum dots and their versatile applications in multiplexed bioimaging research.
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Affiliation(s)
- K. David Wegner
- NanoBioPhotonics
- Institut d'Electronique Fondamentale
- Université Paris-Sud
- 91405 Orsay Cedex
- France
| | - Niko Hildebrandt
- NanoBioPhotonics
- Institut d'Electronique Fondamentale
- Université Paris-Sud
- 91405 Orsay Cedex
- France
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68
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Lane L, Smith AM, Lian T, Nie S. Compact and blinking-suppressed quantum dots for single-particle tracking in live cells. J Phys Chem B 2014; 118:14140-7. [PMID: 25157589 PMCID: PMC4266335 DOI: 10.1021/jp5064325] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 08/25/2014] [Indexed: 02/06/2023]
Abstract
Quantum dots (QDs) offer distinct advantages over organic dyes and fluorescent proteins for biological imaging applications because of their brightness, photostability, and tunability. However, a major limitation is that single QDs emit fluorescent light in an intermittent on-and-off fashion called "blinking". Here we report the development of blinking-suppressed, relatively compact QDs that are able to maintain their favorable optical properties in aqueous solution. Specifically, we show that a linearly graded alloy shell can be grown on a small CdSe core via a precisely controlled layer-by-layer process, and that this graded shell leads to a dramatic suppression of QD blinking in both organic solvents and water. A substantial portion (>25%) of the resulting QDs does not blink (more than 99% of the time in the bright or "on" state). Theoretical modeling studies indicate that this type of linearly graded shell not only can minimize charge carrier access to surface traps but also can reduce lattice defects, both of which are believed to be responsible for carrier trapping and QD blinking. Further, we have evaluated the biological utility of blinking-suppressed QDs coated with polyethylene glycol (PEG)-based ligands and multidentate ligands. The results demonstrate that their optical properties are largely independent of surface coatings and solvating media, and that the blinking-suppressed QDs can provide continuous trajectories in live-cell receptor tracking studies.
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Affiliation(s)
- Lucas
A. Lane
- Departments
of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, United States
| | - Andrew M. Smith
- Department
of Bioengineering, University of Illinois
at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Tianquan Lian
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Shuming Nie
- Departments
of Biomedical Engineering and Chemistry, Emory University and Georgia Institute of Technology, Atlanta, Georgia 30322, United States
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69
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The AAA3 domain of cytoplasmic dynein acts as a switch to facilitate microtubule release. Nat Struct Mol Biol 2014; 22:73-80. [PMID: 25486306 PMCID: PMC4286497 DOI: 10.1038/nsmb.2930] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 11/06/2014] [Indexed: 11/24/2022]
Abstract
Cytoplasmic dynein is an AAA+ motor responsible for intracellular cargo transport and force generation along microtubules (MTs). Unlike kinesin and myosin, dynein contains multiple ATPase subunits, with AAA1 serving as the primary catalytic site. ATPase activity at AAA3 is also essential for robust motility, but its role in dynein’s mechanochemical cycle remains unclear. Here, we introduced transient pauses in Saccharomyces cerevisiae dynein motility by using a slowly hydrolyzing ATP analog. Analysis of pausing behavior revealed that AAA3 hydrolyzes nucleotide an order of magnitude slower than AAA1 and the two sites do not coordinate. ATPase mutations to AAA3 abolish the ability of dynein to modulate MT release. Nucleotide hydrolysis at AAA3 lifts this “MT gate” to fast motility. These results suggest that AAA3 acts as a switch that repurposes cytoplasmic dynein for fast cargo transport and MT anchoring tasks in cells.
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70
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Würth C, Geißler D, Behnke T, Kaiser M, Resch-Genger U. Critical review of the determination of photoluminescence quantum yields of luminescent reporters. Anal Bioanal Chem 2014; 407:59-78. [DOI: 10.1007/s00216-014-8130-z] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/15/2014] [Accepted: 08/22/2014] [Indexed: 12/13/2022]
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71
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Fili N, Toseland CP. Fluorescence and labelling: how to choose and what to do. ACTA ACUST UNITED AC 2014; 105:1-24. [PMID: 25095988 DOI: 10.1007/978-3-0348-0856-9_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This chapter provides an overview of fluorescent labelling of different reactants related to the biochemistry of motor proteins. The fluorescent properties of different labels and the advantages and disadvantages of the labelling methods are discussed. This will allow for a careful selection of fluorescent proteins for different applications relating to motor proteins.
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Affiliation(s)
- Natalia Fili
- Department of Cellular Physiology, Ludwig-Maximilians-Universität München, Schillerstrasse. 44, 80336, Munich, Germany,
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72
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DeWitt M, Schenkel T, Yildiz A. Fluorescence tracking of motor proteins in vitro. ACTA ACUST UNITED AC 2014; 105:211-34. [PMID: 25095997 DOI: 10.1007/978-3-0348-0856-9_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Motor proteins convert the chemical energy of adenosine triphosphate (ATP) hydrolysis into directed movement along filamentous tracks, such as DNA, microtubule, and actin. The motile properties of motors are essential to their wide variety of cellular functions, including cargo transport, mitosis, cell motility, nuclear positioning, and ciliogenesis. Detailed understanding of the biophysical mechanisms of motor motility is therefore essential to understanding the physical basis of these processes. In which direction is the motor going? How fast and how far can a single motor walk down its track? How is ATP hydrolysis coupled to directed motion? How do multiple subunits of a motor coordinate with each other during motility? These questions can be addressed directly by tracking motors at a single-molecule level. This chapter will focus on high-resolution fluorescence tracking techniques of the processive cytoskeletal motors: myosins, kinesins, and cytoplasmic dynein. We outline the theoretical and practical considerations for studying these motors in vitro using fluorescence tracking at nanometer precision.
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Affiliation(s)
- Mark DeWitt
- Biophysics Graduate Group and Physics Department, University of California, Berkeley, CA, 94720, USA
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73
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Wei L, Zhou P, Yang Q, Yang Q, Ma M, Chen B, Xiao L. Fabrication of bright and small size semiconducting polymer nanoparticles for cellular labelling and single particle tracking. NANOSCALE 2014; 6:11351-11358. [PMID: 25141182 DOI: 10.1039/c4nr03293d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this work, we demonstrate a convenient and robust strategy for efficient fabrication of high fluorescence quantum yield (QY, 49.8 ± 3%) semiconducting polymer nanoparticles (SPNs), with size comparable with semiconductor quantum dots (Qdots). The SPNs were synthesized by co-precipitation of hydrophobic semiconducting polymer together with amphiphilic multidentate polymer. Comprehensive spectroscopic and microscopic characterizations showed that the SPNs possess superior photophysical performance, with excellent fluorescence brightness and reduced photoblinking in contrast with Qdots, as well as good photostability compared to a fluorescent protein of a similar size, phycoerythrin. More importantly, by conjugating membrane biomarkers onto the surface of SPNs, it was found that they were not only suitable for specific cellular labelling but also for single particle tracking because of the improved optical performance.
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Affiliation(s)
- Lin Wei
- Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of Phytochemical R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, P. R. China.
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74
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Zhao W, Dong S, Sun L, Wang Q, Gai H. Investigating the photostability of quantum dots at the single-molecule level. Chem Asian J 2014; 9:3542-8. [PMID: 25234334 DOI: 10.1002/asia.201402453] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/15/2014] [Indexed: 11/11/2022]
Abstract
Quantum dots (QDs) have shown great potential to provide spatial, temporal, and structural information for biological systems. However, blinking, photobleaching, and spectral blueshift are adverse effects on their practical applications in biomedical research. An investigation of the effects of six reducing agents including cysteine (Cys), 1,4-dithiothreitol (DTT), ethyl gallate (EG), L-glutathione (GSH), mercaptoacetic acid (MAA), and thiourea (TU) on the photostability of single QDs was studied. Our experiments demonstrate that both DTT and EG effectively inhibit blinking, photobleaching, and spectral blueshift. GSH molecules block blinking and photobleaching of QDs. The other reagents, Cys, MAA, and TU, only have the ability to counteract blinking. Possible explanations are given on the basis of research evidence. The results suggest possibilities for significant improvements in QDs for biological applications by adjusting the environmental conditions.
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Affiliation(s)
- Wenfeng Zhao
- School of Chemistry and Chemical Engineering, Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu (P.R. China), Fax: (+86) 516-83536972
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75
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Ichimura T, Jin T, Fujita H, Higuchi H, Watanabe TM. Nano-scale measurement of biomolecules by optical microscopy and semiconductor nanoparticles. Front Physiol 2014; 5:273. [PMID: 25120488 PMCID: PMC4114191 DOI: 10.3389/fphys.2014.00273] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/05/2014] [Indexed: 12/14/2022] Open
Abstract
Over the past decade, great developments in optical microscopy have made this technology increasingly compatible with biological studies. Fluorescence microscopy has especially contributed to investigating the dynamic behaviors of live specimens and can now resolve objects with nanometer precision and resolution due to super-resolution imaging. Additionally, single particle tracking provides information on the dynamics of individual proteins at the nanometer scale both in vitro and in cells. Complementing advances in microscopy technologies has been the development of fluorescent probes. The quantum dot, a semi-conductor fluorescent nanoparticle, is particularly suitable for single particle tracking and super-resolution imaging. This article overviews the principles of single particle tracking and super resolution along with describing their application to the nanometer measurement/observation of biological systems when combined with quantum dot technologies.
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Affiliation(s)
- Taro Ichimura
- Laboratory for Comprehensive Bioimaging, RIKEN Quantitative Biology Center Suita, Osaka, Japan
| | - Takashi Jin
- Laboratory for Nano-Bio Probes, RIKEN Quantitative Biology Center Suita, Osaka, Japan ; Graduate School of Frontier Biosciences, Osaka University Suita, Osaka, Japan ; WPI, Immunology Frontier Research Center, Osaka University Suita, Osaka, Japan
| | - Hideaki Fujita
- Laboratory for Comprehensive Bioimaging, RIKEN Quantitative Biology Center Suita, Osaka, Japan ; WPI, Immunology Frontier Research Center, Osaka University Suita, Osaka, Japan
| | - Hideo Higuchi
- Department of Physics, School of Science, The University of Tokyo Bunkyo, Tokyo, Japan
| | - Tomonobu M Watanabe
- Laboratory for Comprehensive Bioimaging, RIKEN Quantitative Biology Center Suita, Osaka, Japan ; Graduate School of Frontier Biosciences, Osaka University Suita, Osaka, Japan ; WPI, Immunology Frontier Research Center, Osaka University Suita, Osaka, Japan
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76
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van Schooten KJ, Boehme C, Lupton JM. Coherent magnetic resonance of nanocrystal quantum-dot luminescence as a window to blinking mechanisms. Chemphyschem 2014; 15:1737-46. [PMID: 24756986 DOI: 10.1002/cphc.201400081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/04/2014] [Indexed: 11/08/2022]
Abstract
Blinking of colloidal nanocrystal quantum dots, random intermittency in the stream of photons emitted by single particles, has long commanded the curiosity of researchers. Why does the particle suddenly shut off, and what are the pathways to quench emission? Single-particle microscopy is not the only way to approach these fundamental questions on the interaction of light and matter: time-domain sub-ensemble spectroscopies can also yield relevant information on microscopic electronic processes. We illustrate recent advances in pulsed optically detected magnetic resonance and highlight the conceptual relevance to unravelling mechanisms controlling intermittency on the single-particle level. Magnetic resonance reveals two distinct luminescence quenching channels, which appear to be related to those previously surmised from single-particle studies: a trapped charge-separated state in which the exciton is quenched by dissociation and the particle remains neutral; and a charged state of the particle in which spin-dependent Auger recombination quenches luminescence.
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Affiliation(s)
- Kipp J van Schooten
- Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112-0830 (USA)
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77
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Flessau S, Wolter C, Pöselt E, Kröger E, Mews A, Kipp T. Fluorescence spectroscopy of individual semiconductor nanoparticles in different ethylene glycols. Phys Chem Chem Phys 2014; 16:10444-55. [PMID: 24788878 DOI: 10.1039/c4cp00443d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The optical properties of single colloidal semiconductor nanoparticles (NPs) are considerably influenced by the direct environment of the NPs. Here, the influence of different liquid and solid glycol matrices on CdSe-based NPs is investigated. Since the fluorescence of individual NPs varies from one NP to another, it is highly desirable to study the very same individual NPs in different matrices. This was accomplished by immobilizing NPs in a liquid cell sample holder or in microfluidic devices. The samples have been investigated by space-resolved wide-field fluorescence microscopy and energy- and time-resolved confocal scanning fluorescence microscopy with respect to fluorescence intensities, emission energies, blinking behavior, and fluorescence decay dynamics of individual NPs. During the measurements the NPs were exposed to air, to liquid ethylene glycols H(OCH2CH2)nOH (also called EGn) with different chain lengths (1 ≤ n ≤ 7), to liquid 2-methylpentane-2,3-diol, or to solid polyethylene oxide. It was found that EG6-7 (also known as PEG 300) is very well suited as a liquid matrix or solvent for experiments that correlate chemical and physical modifications of the surface and of the immediate environment of individual NPs to their fluorescence properties since it leads to intense and stable fluorescence emission of the NPs.
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Affiliation(s)
- Sandra Flessau
- Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
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78
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Silva-López EI, Edens LE, Barden AO, Keller DJ, Brozik JA. Conditions for liposome adsorption and bilayer formation on BSA passivated solid supports. Chem Phys Lipids 2014; 183:91-9. [PMID: 24911903 DOI: 10.1016/j.chemphyslip.2014.06.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 06/02/2014] [Accepted: 06/04/2014] [Indexed: 12/14/2022]
Abstract
Planar solid supported lipid membranes that include an intervening bovine serum albumen (BSA) cushion can greatly reduce undesirable interactions between reconstituted membrane proteins and the underlying substrate. These hetero-self-assemblies reduce frictional coupling by shielding reconstituted membrane proteins from the strong surface charge of the underlying substrate, thereby preventing them from strongly sticking to the substrate themselves. The motivation for this work is to describe the conditions necessary for liposome adsorption and bilayer formation on these hetero-self-assemblies. Described here are experiments that show that the state of BSA is critically important to whether a lipid bilayer is formed or intact liposomes are adsorbed to the BSA passivated surface. It is shown that a smooth layer of native BSA will readily promote lipid bilayer formation while BSA that has been denatured either chemically or by heat will not. Atomic force microscopy (AFM) and fluorescence microscopy was used to characterize the surfaces of native, heat denatured, and chemically reduced BSA. The mobility of several zwitterionic and negatively charged lipid combinations has been measured using fluorescence recovery after photobleaching (FRAP). From these measurements diffusion constants and percent recoveries have been determined and tabulated. The effect of high concentrations of beta-mercaptoethanol (β-ME) on liposome formation as well as bilayer formation was also explored.
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Affiliation(s)
- Elsa I Silva-López
- Department of Chemistry, Washington State University, PO Box 644630, Pullman, WA 99164-4630, United States
| | - Lance E Edens
- Department of Chemistry and Biological Chemistry, University of New Mexico, Albuquerque, NM 87131-0001, United States
| | - Adam O Barden
- Department of Chemistry, Washington State University, PO Box 644630, Pullman, WA 99164-4630, United States
| | - David J Keller
- Department of Chemistry and Biological Chemistry, University of New Mexico, Albuquerque, NM 87131-0001, United States
| | - James A Brozik
- Department of Chemistry, Washington State University, PO Box 644630, Pullman, WA 99164-4630, United States.
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79
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Somogyi B, Gali A. Computational design of in vivo biomarkers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:143202. [PMID: 24651562 DOI: 10.1088/0953-8984/26/14/143202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Fluorescent semiconductor nanocrystals (or quantum dots) are very promising agents for bioimaging applications because their optical properties are superior compared to those of conventional organic dyes. However, not all the properties of these quantum dots suit the stringent criteria of in vivo applications, i.e. their employment in living organisms that might be of importance in therapy and medicine. In our review, we first summarize the properties of an 'ideal' biomarker needed for in vivo applications. Despite recent efforts, no such hand-made fluorescent quantum dot exists that may be considered as 'ideal' in this respect. We propose that ab initio atomistic simulations with predictive power can be used to design 'ideal' in vivo fluorescent semiconductor nanoparticles. We briefly review such ab initio methods that can be applied to calculate the electronic and optical properties of very small nanocrystals, with extra emphasis on density functional theory (DFT) and time-dependent DFT which are the most suitable approaches for the description of these systems. Finally, we present our recent results on this topic where we investigated the applicability of nanodiamonds and silicon carbide nanocrystals for in vivo bioimaging.
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Affiliation(s)
- Bálint Somogyi
- Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki út 8., H-1111, Budapest, Hungary
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80
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Mangum BD, Sampat S, Ghosh Y, Hollingsworth JA, Htoon H, Malko AV. Influence of the core size on biexciton quantum yield of giant CdSe/CdS nanocrystals. NANOSCALE 2014; 6:3712-3720. [PMID: 24569861 DOI: 10.1039/c3nr06558h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We present a systematic study of photoluminescence (PL) emission intensity and biexciton (BX) quantum yields (QYBX) in individual "giant" CdSe/CdS nanocrystals (g-NCs) as a function of g-NC core size and shell thickness. We show that g-NC core size significantly affects QYBX and can be utilized as an effective tuning parameter towards higher QYBX while keeping the total volume of the g-NC constant. Specifically, we observe that small-core (2.2 nm diameter) CdSe/CdS NCs with a volume of ∼200 nm(3) (shell comprises 4 CdS monolayers) show very low average and maximum QYBX's of ∼3 and 7%, respectively. In contrast, same-volume medium-core (3 nm diameter) NCs afford higher average values of ∼10%, while QYBX's of ∼30% are achieved for same-volume large-core (5.5 nm diameter) CdSe/CdS NCs, with some approaching ∼80%. These observations underline the influence of the g-NC core size on the evolution of PL emissive states in multi-shell NCs. Moreover, our study also reveals that the use of long anneal times in the growth of CdS shells plays a critical role in achieving high QYBX.
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Affiliation(s)
- Benjamin D Mangum
- Materials Physics and Applications Division, Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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81
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Shibu ES, Hamada M, Nakanishi S, Wakida SI, Biju V. Photoluminescence of CdSe and CdSe/ZnS quantum dots: Modifications for making the invisible visible at ensemble and single-molecule levels. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.10.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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82
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Hollingsworth JA. Nanoscale engineering facilitated by controlled synthesis: From structure to function. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2013.09.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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83
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Liu B, Li C, Yang D, Hou Z, Ma P, Cheng Z, Lian H, Huang S, Lin J. Upconversion-Luminescent Core/Mesoporous-Silica-Shell-Structured β-NaYF4:Yb3+,Er3+@SiO2@mSiO2Composite Nanospheres: Fabrication and Drug-Storage/Release Properties. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201301460] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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84
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Begum R, Sahoo AK, Ghosh SS, Chattopadhyay A. Recovering hidden quanta of Cu(2+)-doped ZnS quantum dots in reductive environment. NANOSCALE 2014; 6:953-961. [PMID: 24288124 DOI: 10.1039/c3nr05280j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report that photoluminescence of doped quantum dots (Qdots)-which was otherwise lost in the oxidized form of the dopant-could be recovered in chemical or cellular reducing environment. For example, as-synthesized Cu(2+)-doped zinc sulfide (ZnS) Qdots in water medium showed weak emission with a peak at 420 nm, following excitation with UV light (320 nm). However, addition of reducing agent led to the appearance of green emission with a peak at 540 nm and with quantum yield as high as 10%, in addition to the weak peak now appearing as a shoulder. The emission disappeared in the presence of an oxidizing agent or with time under ambient conditions. X-Ray photoelectron spectroscopic (XPS) and electron spin resonance (ESR) measurements suggested the presence of Cu(2+) in the as-synthesized Qdots, while formation of its reduced form was indicated (by ESR results) following treatment with a reducing agent. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) studies confirmed the formation of ZnS nanocrystals, the size and shape of which did not undergo any change in the presence of a reducing or oxidizing agent. Nanoparticulate forms of the Qdots and chitosan (a biopolymer) composite exhibited similar emission characteristics. Interestingly, when mammalian cancer cells or non-cancerous cells were treated with the composite nanoparticles (NPs), characteristic green fluorescence was observed. Further, the intensity of the fluorescence diminished when the cells were treated later with pyrogallol-a known reactive oxygen species generator. Overall, the results indicated a new way of probing the reducing nature of mammalian cells using the emission properties of the Qdot based on the redox state of its dopant.
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Affiliation(s)
- Raihana Begum
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati-781039, India.
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85
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Dong C, Liu H, Zhang A, Ren J. Controllable Blinking-to-Nonblinking Behavior of Aqueous CdTeS Alloyed Quantum Dots. Chemistry 2014; 20:1940-6. [DOI: 10.1002/chem.201303605] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/21/2013] [Indexed: 11/06/2022]
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86
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87
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Qin H, Niu Y, Meng R, Lin X, Lai R, Fang W, Peng X. Single-Dot Spectroscopy of Zinc-Blende CdSe/CdS Core/Shell Nanocrystals: Nonblinking and Correlation with Ensemble Measurements. J Am Chem Soc 2013; 136:179-87. [DOI: 10.1021/ja4078528] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Haiyan Qin
- Center
for Chemistry of Novel and High-Performance Materials, and Department
of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Yuan Niu
- Center
for Chemistry of Novel and High-Performance Materials, and Department
of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Renyang Meng
- Center
for Chemistry of Novel and High-Performance Materials, and Department
of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Xing Lin
- State
Key Laboratory of Modern Optical Instrumentation, Department of Optical
Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Runchen Lai
- Center
for Chemistry of Novel and High-Performance Materials, and Department
of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Wei Fang
- State
Key Laboratory of Modern Optical Instrumentation, Department of Optical
Engineering, Zhejiang University, Hangzhou, 310027, P. R. China
| | - Xiaogang Peng
- Center
for Chemistry of Novel and High-Performance Materials, and Department
of Chemistry, Zhejiang University, Hangzhou, 310027, P. R. China
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88
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Arnspang EC, Schwartzentruber J, Clausen MP, Wiseman PW, Lagerholm BC. Bridging the gap between single molecule and ensemble methods for measuring lateral dynamics in the plasma membrane. PLoS One 2013; 8:e78096. [PMID: 24324577 PMCID: PMC3850922 DOI: 10.1371/journal.pone.0078096] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 09/17/2013] [Indexed: 11/22/2022] Open
Abstract
The lateral dynamics of proteins and lipids in the mammalian plasma membrane are heterogeneous likely reflecting both a complex molecular organization and interactions with other macromolecules that reside outside the plane of the membrane. Several methods are commonly used for characterizing the lateral dynamics of lipids and proteins. These experimental and data analysis methods differ in equipment requirements, labeling complexities, and further oftentimes give different results. It would therefore be very convenient to have a single method that is flexible in the choice of fluorescent label and labeling densities from single molecules to ensemble measurements, that can be performed on a conventional wide-field microscope, and that is suitable for fast and accurate analysis. In this work we show that k-space image correlation spectroscopy (kICS) analysis, a technique which was originally developed for analyzing lateral dynamics in samples that are labeled at high densities, can also be used for fast and accurate analysis of single molecule density data of lipids and proteins labeled with quantum dots (QDs). We have further used kICS to investigate the effect of the label size and by comparing the results for a biotinylated lipid labeled at high densities with Atto647N-strepatvidin (sAv) or sparse densities with sAv-QDs. In this latter case, we see that the recovered diffusion rate is two-fold greater for the same lipid and in the same cell-type when labeled with Atto647N-sAv as compared to sAv-QDs. This data demonstrates that kICS can be used for analysis of single molecule data and furthermore can bridge between samples with a labeling densities ranging from single molecule to ensemble level measurements.
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Affiliation(s)
- Eva C. Arnspang
- Department of Physics, Chemistry and Pharmacy, MEMPHYS-Center for Biomembrane Physics & DaMBIC – Danish Molecular Biomedical Imaging Center, University of Southern Denmark, Odense, Denmark
| | | | - Mathias P. Clausen
- Department of Physics, Chemistry and Pharmacy, MEMPHYS-Center for Biomembrane Physics & DaMBIC – Danish Molecular Biomedical Imaging Center, University of Southern Denmark, Odense, Denmark
| | - Paul W. Wiseman
- Department of Physics and Department of Chemistry, McGill University, Montreal, Canada
| | - B. Christoffer Lagerholm
- Department of Physics, Chemistry and Pharmacy, MEMPHYS-Center for Biomembrane Physics & DaMBIC – Danish Molecular Biomedical Imaging Center, University of Southern Denmark, Odense, Denmark
- * E-mail:
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89
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Wang Y, Fruhwirth G, Cai E, Ng T, Selvin PR. 3D super-resolution imaging with blinking quantum dots. NANO LETTERS 2013; 13:5233-41. [PMID: 24093439 PMCID: PMC3874875 DOI: 10.1021/nl4026665] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Quantum dots are promising candidates for single molecule imaging due to their exceptional photophysical properties, including their intense brightness and resistance to photobleaching. They are also notorious for their blinking. Here we report a novel way to take advantage of quantum dot blinking to develop an imaging technique in three-dimensions with nanometric resolution. We first applied this method to simulated images of quantum dots and then to quantum dots immobilized on microspheres. We achieved imaging resolutions (fwhm) of 8-17 nm in the x-y plane and 58 nm (on coverslip) or 81 nm (deep in solution) in the z-direction, approximately 3-7 times better than what has been achieved previously with quantum dots. This approach was applied to resolve the 3D distribution of epidermal growth factor receptor (EGFR) molecules at, and inside of, the plasma membrane of resting basal breast cancer cells.
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Affiliation(s)
- Yong Wang
- Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Physics of the Living Cell, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Gilbert Fruhwirth
- The Richard Dimbleby Department of Cancer Research, Randall Division of Cell & Molecular Biophysics and Division of Cancer Studies, King’s College London
| | - En Cai
- Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Physics of the Living Cell, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Tony Ng
- The Richard Dimbleby Department of Cancer Research, Randall Division of Cell & Molecular Biophysics and Division of Cancer Studies, King’s College London
| | - Paul R. Selvin
- Physics Department, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Physics of the Living Cell, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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90
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91
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Affiliation(s)
- Jens Michaelis
- Biophysics
Institute, Faculty of Natural Sciences, Ulm University, Albert-Einstein-Allee
11, 89081 Ulm, Germany
- Center
for Integrated Protein Science Munich (CIPSM), Department
of Chemistry and Biochemistry, Munich University, Butenandtstrasse 5-13, 81377 München, Germany
| | - Barbara Treutlein
- Department
of Bioengineering, Stanford University, James H. Clark Center, E-300, 318
Campus Drive, Stanford, California 94305-5432, United States
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92
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Yang G, Gai S, Qu F, Yang P. SiO2@YBO3:Eu3+ hollow mesoporous spheres for drug delivery vehicle. ACS APPLIED MATERIALS & INTERFACES 2013; 5:5788-5796. [PMID: 23705794 DOI: 10.1021/am401349z] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A novel bifunctional (fluorescent, mesoporous) hollow sphere was prepared by coating luminescent YBO3:Eu(3+) nanoparticles onto uniform hollow mesoporous silica spheres (HMSs), derived from an etching strategy using spherical Fe3O4 as templates. The composites exhibit typical mesoporous shells, large interior space, high surface area, and well dispersed nanospheres with controlled size. In addition, the textural properties including the specific surface and pore volume can be easily altered by simply tuning of the spherical Fe3O4 cores. Upon ultraviolet (UV) excitation, the composite shows the characteristic (5)D0-(7)F1-4 red emission lines of Eu(3+) even after loading of the model drug. The composite with a large surface area and cavity was used as the host for loading the anticancer drug doxorubicin hydrochloride (DOX). It is observed that the multifunctional composites exhibit an obvious sustained release property and released in texture- and pH-sensitive patterns. Particularly, the down-conversion (DC) fluorescence intensity of the bifunctional vehicle increases with the release of drug molecules, making it possible to track the position and the drug release amount of the drug carrier system and to detect them by the change of fluorescence intensity.
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Affiliation(s)
- Guixin Yang
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, Harbin Engineering University, Harbin 150001, PR China
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93
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Chen O, Zhao J, Chauhan VP, Cui J, Wong C, Harris DK, Wei H, Han HS, Fukumura D, Jain RK, Bawendi MG. Compact high-quality CdSe-CdS core-shell nanocrystals with narrow emission linewidths and suppressed blinking. NATURE MATERIALS 2013; 12:445-51. [PMID: 23377294 PMCID: PMC3677691 DOI: 10.1038/nmat3539] [Citation(s) in RCA: 649] [Impact Index Per Article: 59.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 12/04/2012] [Indexed: 05/17/2023]
Abstract
High particle uniformity, high photoluminescence quantum yields, narrow and symmetric emission spectral lineshapes and minimal single-dot emission intermittency (known as blinking) have been recognized as universal requirements for the successful use of colloidal quantum dots in nearly all optical applications. However, synthesizing samples that simultaneously meet all these four criteria has proven challenging. Here, we report the synthesis of such high-quality CdSe-CdS core-shell quantum dots in an optimized process that maintains a slow growth rate of the shell through the use of octanethiol and cadmium oleate as precursors. In contrast with previous observations, single-dot blinking is significantly suppressed with only a relatively thin shell. Furthermore, we demonstrate the elimination of the ensemble luminescence photodarkening that is an intrinsic consequence of quantum dot blinking statistical ageing. Furthermore, the small size and high photoluminescence quantum yields of these novel quantum dots render them superior in vivo imaging agents compared with conventional quantum dots. We anticipate these quantum dots will also result in significant improvement in the performance of quantum dots in other applications such as solid-state lighting and illumination.
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Affiliation(s)
- Ou Chen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Jing Zhao
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Vikash P. Chauhan
- Massachusetts General Hospital and Harvard Medical School, 100 Blossom St., Boston, MA 02114 (USA)
| | - Jian Cui
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Cliff Wong
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Daniel K. Harris
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - He Wei
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Hee-Sun Han
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
| | - Dai Fukumura
- Massachusetts General Hospital and Harvard Medical School, 100 Blossom St., Boston, MA 02114 (USA)
| | - Rakesh K. Jain
- Massachusetts General Hospital and Harvard Medical School, 100 Blossom St., Boston, MA 02114 (USA)
| | - Moungi G. Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge MA 02139 (USA)
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94
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Hollingsworth JA. Heterostructuring Nanocrystal Quantum Dots Toward Intentional Suppression of Blinking and Auger Recombination. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2013; 25:1318-1331. [PMID: 24062602 PMCID: PMC3778929 DOI: 10.1021/cm304161d] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
At the level of a single particle, nanocrystal quantum dots (NQDs) are observed to fluoresce intermittently or "blink." They are also characterized by an efficient non-radiative recombination process known as Auger Recombination (AR). Recently, new approaches to NQD heterostructuring have been developed that directly impact both blinking and AR, resulting in dramatic suppression of these unwanted processes. The three successful hetero-NQD motifs are reviewed here: (1) interfacial alloying, (2) thick or "giant" shells, and (3) specific type-II electronic structures. These approaches, which rely on modifying or tuning internal NQD core/shell structures, are compared with alternative strategies for blinking suppression that rely, instead, on surface modifications or surface-mediated interactions. Finally, in each case, the unique synthetic approaches or challenges addressed that have driven the realization of novel and important functionality are discussed, along with the implications for development of a comprehensive 'materials design' strategy for blinking and AR-suppressed heterostructured NQDs.
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Affiliation(s)
- Jennifer A Hollingsworth
- Material Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM 8754
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95
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Toseland CP. Fluorescent labeling and modification of proteins. J Chem Biol 2013; 6:85-95. [PMID: 24432126 PMCID: PMC3691395 DOI: 10.1007/s12154-013-0094-5] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/01/2013] [Indexed: 10/27/2022] Open
Abstract
This review provides an outline for fluorescent labeling of proteins. Fluorescent assays are very diverse providing the most sensitive and robust methods for observing biological processes. Here, different types of labels and methods of attachment are discussed in combination with their fluorescent properties. The advantages and disadvantages of these different methods are highlighted, allowing the careful selection for different applications, ranging from ensemble spectroscopy assays through to single-molecule measurements.
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Affiliation(s)
- Christopher P. Toseland
- Institut für Zelluläre Physiologie and Center for NanoScience (CeNS), Physiologisches Institut, Ludwig Maximilians Universität, Munich, 80336 Germany
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96
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Hughes CD, Wang H, Ghodke H, Simons M, Towheed A, Peng Y, Van Houten B, Kad NM. Real-time single-molecule imaging reveals a direct interaction between UvrC and UvrB on DNA tightropes. Nucleic Acids Res 2013; 41:4901-12. [PMID: 23511970 PMCID: PMC3643590 DOI: 10.1093/nar/gkt177] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Nucleotide excision DNA repair is mechanistically conserved across all kingdoms of life. In prokaryotes, this multi-enzyme process requires six proteins: UvrA–D, DNA polymerase I and DNA ligase. To examine how UvrC locates the UvrB–DNA pre-incision complex at a site of damage, we have labeled UvrB and UvrC with different colored quantum dots and quantitatively observed their interactions with DNA tightropes under a variety of solution conditions using oblique angle fluorescence imaging. Alone, UvrC predominantly interacts statically with DNA at low salt. Surprisingly, however, UvrC and UvrB together in solution bind to form the previously unseen UvrBC complex on duplex DNA. This UvrBC complex is highly motile and engages in unbiased one-dimensional diffusion. To test whether UvrB makes direct contact with the DNA in the UvrBC–DNA complex, we investigated three UvrB mutants: Y96A, a β-hairpin deletion and D338N. These mutants affected the motile properties of the UvrBC complex, indicating that UvrB is in intimate contact with the DNA when bound to UvrC. Given the in vivo excess of UvrB and the abundance of UvrBC in our experiments, this newly identified complex is likely to be the predominant form of UvrC in the cell.
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Affiliation(s)
- Craig D Hughes
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
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97
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Song N, Zhu H, Liu Z, Huang Z, Wu D, Lian T. Unraveling the exciton quenching mechanism of quantum dots on antimony-doped SnO₂ films by transient absorption and single dot fluorescence spectroscopy. ACS NANO 2013; 7:1599-1608. [PMID: 23281781 DOI: 10.1021/nn3054494] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Integrating quantum dots (QDs) into modern optoelectronic devices requires an understanding of how a transparent conducting substrate affects the properties of QDs, especially their excited-state dynamics. Here, the exciton quenching dynamics of core/multishell (CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML)) quantum dots deposited on glass, tin oxide (SnO₂), and antimony (Sb)-doped tin oxide (ATO) films are studied by transient absorption and single QD fluorescence spectroscopic methods. By comparing ensemble-averaged fluorescence decay and transient absorption kinetics, we show that, for QDs on SnO₂, the exciton is quenched by electron transfer from the QD to SnO₂. At the QD-ATO interface, much faster exciton quenching rates are observed and attributed to fast Auger recombination in charged QDs formed by Fermi level equilibration between the QD and n-doped ATO. Single QDs on SnO₂ and ATO show similar blinking dynamics with correlated fluctuations of emission intensities and lifetimes. Compared to QDs on SnO₂, QDs on ATO films show larger variation of average exciton quenching rates, which is attributed to a broad distribution of the number of charges and nature of charging sites on the QD surface.
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Affiliation(s)
- Nianhui Song
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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98
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Rostami A, Dolatyari M, Amini E, Rasooli H, Baghban H, Miri S. Sensitive, Fast, Solution-Processed Ultraviolet Detectors Based on Passivated Zinc Oxide Nanorods. Chemphyschem 2013; 14:554-9. [DOI: 10.1002/cphc.201200660] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 11/28/2012] [Indexed: 11/08/2022]
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99
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Chaturbedy P, Chatterjee S, Selvi RB, Bhat A, Kavitha MK, Tiwari V, Patel AB, Kundu TK, Maji TK, Eswaramoothy M. Multifunctional carbon nanospheres with magnetic and luminescent probes: probable brain theranostic agents. J Mater Chem B 2013; 1:939-945. [DOI: 10.1039/c2tb00134a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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100
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Sun R, Chen K, Wu X, Zhao D, Sun Z. Controlled synthesis and enhanced luminescence of europium-doped fluorine-substituted hydroxyapatite nanoparticles. CrystEngComm 2013. [DOI: 10.1039/c3ce26973f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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