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Gabriel M, Anzalone A, Gratton E, Estrada LC. A tracking-based nanoimaging method for fast detection of surfaces' inhomogeneities using gold nanoparticles. Microsc Res Tech 2019; 82:1835-1842. [PMID: 31318476 DOI: 10.1002/jemt.23350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/06/2019] [Indexed: 11/11/2022]
Abstract
The localization of surfaces inhomogeneities is central to many areas of technology, chemistry and biology, ranging from surface defects in industry to the identification and screening of early bio-defects inside cells. The development of methods that enable direct, sensitive, and rapid detection of those inhomogeneities is both relevant and timely. To address this challenge, we developed a far-field nanoimaging method to detect the presence of surface's nanodefects that modify the signal emitted by gold nanoparticles (AuNPs) under laser irradiation. Our technique is based on the formation of hot spots due to the confinement of light in the proximity of the AuNP, whose positions depend on the polarization direction of the incident beam. An inhomogeneity is detected as an increase in the intensity collected from the hot spots when a laser beam is orbiting the nanoparticle and the incident polarization direction of the laser beam is changed periodically.
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Affiliation(s)
- Manuela Gabriel
- Laboratorio de Electrónica Cuántica, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Ciudad Universitaria, Buenos Aires, Argentina
| | - Andrea Anzalone
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, California
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, California
| | - Laura C Estrada
- Laboratorio de Electrónica Cuántica, Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA-CONICET, Ciudad Universitaria, Buenos Aires, Argentina
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Zalami D, Grimm O, Schacher FH, Gerken U, Köhler J. Non-invasive study of the three-dimensional structure of nanoporous triblock terpolymer membranes. SOFT MATTER 2018; 14:9750-9754. [PMID: 30507995 DOI: 10.1039/c8sm01870g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nanoporous media are of great importance for drug delivery or filtration. Typically the pore structure of such media is characterized using high-resolution techniques such as electron microscopy or atomic force microscopy. However, these techniques are restricted to the surface of the material and/or are highly invasive. In a proof-of-concept experiment we have employed three-dimensional single-particle orbit tracking for testing the three-dimensional pore structure of a liquid filled nanoporous polystyrene-block-polyisoprene-block-poly(N-isopropylacrylamide) (PS-b-PI-b-PNiPAAm) triblock terpolymer membrane. Using fluorescent tracers with a diameter of about 10% of the relevant void structures, the tracking experiments yielded results that were comparable to those obtained from reference experiments using environmental scanning electron microscopy (eSEM). This testifies that single-particle orbit tracking can serve as a useful non-invasive alternative for characterising the structure of nanoporous materials.
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Affiliation(s)
- Daniel Zalami
- Spectroscopy of soft Matter, University of Bayreuth, Universitätsstraße 30, 94557 Bayreuth, Germany.
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Anzalone A, Gabriel M, Estrada LC, Gratton E. Spectral properties of single gold nanoparticles in close proximity to biological fluorophores excited by 2-photon excitation. PLoS One 2015; 10:e0124975. [PMID: 25909648 PMCID: PMC4409109 DOI: 10.1371/journal.pone.0124975] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/19/2015] [Indexed: 11/29/2022] Open
Abstract
Metallic nanoparticles (NPs) are able to modify the excitation and emission rates (plasmonic enhancement) of fluorescent molecules in their close proximity. In this work, we measured the emission spectra of 20 nm Gold Nanoparticles (AuNPs) fixed on a glass surface submerged in a solution of different fluorophores using a spectral camera and 2-photon excitation. While on the glass surface, we observed the presence in the emission at least 3 components: i) second harmonic signal (SHG), ii) a broad emission from AuNPS and iii) fluorescence arising from fluorophores nearby. When on the glass surface, we found that the 3 spectral components have different relative intensities when the incident direction of linear polarization was changed indicating different physical origins for these components. Then we measured by fluctuation correlation spectroscopy (FCS) the scattering and fluorescence signal of the particles alone and in a solution of 100 nM EGFP using the spectral camera or measuring the scattering and fluorescence from the particles. We observed occasional fluorescence bursts when in the suspension we added fluorescent proteins. The spectrum of these burst was devoid of the SHG and of the broad emission in contrast to the signal collected from the gold nanoparticles on the glass surface. Instead we found that the spectrum during the burst corresponded closely to the spectrum of the fluorescent protein. An additional control was obtained by measuring the cross-correlation between the reflection from the particles and the fluorescence arising from EGFP both excited at 488 nm. We found a very weak cross-correlation between the AuNPs and the fluorescence confirming that the burst originate from a few particles with a fluorescence signal.
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Affiliation(s)
- Andrea Anzalone
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States of America
| | - Manuela Gabriel
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States of America
| | - Laura C. Estrada
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States of America
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California Irvine, Irvine, California, United States of America
- Centre for Bioactive Discovery in Health and Ageing, School of Science & Technology, University of New England, Armidale, Australia
- * E-mail:
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Košmrlj A, Cordsen P, Kyrsting A, Otzen DE, Oddershede LB, Jensen MH. A monomer-trimer model supports intermittent glucagon fibril growth. Sci Rep 2015; 5:9005. [PMID: 25758791 PMCID: PMC4355668 DOI: 10.1038/srep09005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/19/2015] [Indexed: 11/23/2022] Open
Abstract
We investigate in vitro fibrillation kinetics of the hormone peptide glucagon at various concentrations using confocal microscopy and determine the glucagon fibril persistence length 60μm. At all concentrations we observe that periods of individual fibril growth are interrupted by periods of stasis. The growth probability is large at high and low concentrations and is reduced for intermediate glucagon concentrations. To explain this behavior we propose a simple model, where fibrils come in two forms, one built entirely from glucagon monomers and one entirely from glucagon trimers. The opposite building blocks act as fibril growth blockers, and this generic model reproduces experimental behavior well.
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Affiliation(s)
- Andrej Košmrlj
- Harvard University, Department of Physics, 17 Oxford Street, Cambridge, MA 02138, USA
| | - Pia Cordsen
- Copenhagen University, Niels Bohr Institute, CMOL, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Anders Kyrsting
- Copenhagen University, Niels Bohr Institute, CMOL, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Daniel E Otzen
- 1] Copenhagen University, Niels Bohr Institute, CMOL, Blegdamsvej 17, DK-2100 Copenhagen, Denmark [2] Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C, Denmark
| | - Lene B Oddershede
- Copenhagen University, Niels Bohr Institute, CMOL, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
| | - Mogens H Jensen
- Copenhagen University, Niels Bohr Institute, CMOL, Blegdamsvej 17, DK-2100 Copenhagen, Denmark
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Anzalone A, Annibale P, Gratton E. 3D orbital tracking in a modified two-photon microscope: an application to the tracking of intracellular vesicles. J Vis Exp 2014:e51794. [PMID: 25350070 DOI: 10.3791/51794] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The objective of this video protocol is to discuss how to perform and analyze a three-dimensional fluorescent orbital particle tracking experiment using a modified two-photon microscope(1). As opposed to conventional approaches (raster scan or wide field based on a stack of frames), the 3D orbital tracking allows to localize and follow with a high spatial (10 nm accuracy) and temporal resolution (50 Hz frequency response) the 3D displacement of a moving fluorescent particle on length-scales of hundreds of microns(2). The method is based on a feedback algorithm that controls the hardware of a two-photon laser scanning microscope in order to perform a circular orbit around the object to be tracked: the feedback mechanism will maintain the fluorescent object in the center by controlling the displacement of the scanning beam(3-5). To demonstrate the advantages of this technique, we followed a fast moving organelle, the lysosome, within a living cell(6,7). Cells were plated according to standard protocols, and stained using a commercially lysosome dye. We discuss briefly the hardware configuration and in more detail the control software, to perform a 3D orbital tracking experiment inside living cells. We discuss in detail the parameters required in order to control the scanning microscope and enable the motion of the beam in a closed orbit around the particle. We conclude by demonstrating how this method can be effectively used to track the fast motion of a labeled lysosome along microtubules in 3D within a live cell. Lysosomes can move with speeds in the range of 0.4-0.5 µm/sec, typically displaying a directed motion along the microtubule network(8).
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Affiliation(s)
- Andrea Anzalone
- Biomedical Engineering, Laboratory for Fluorescence Dynamics, University of California, Irvine
| | - Paolo Annibale
- Biomedical Engineering, Laboratory for Fluorescence Dynamics, University of California, Irvine
| | - Enrico Gratton
- Biomedical Engineering, Laboratory for Fluorescence Dynamics, University of California, Irvine;
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Sun NF, Liu ZA, Huang WB, Tian AL, Hu SY. The research of nanoparticles as gene vector for tumor gene therapy. Crit Rev Oncol Hematol 2014; 89:352-7. [DOI: 10.1016/j.critrevonc.2013.10.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 08/29/2013] [Accepted: 10/02/2013] [Indexed: 01/18/2023] Open
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Dendrimer probes for enhanced photostability and localization in fluorescence imaging. Biophys J 2013; 104:1566-75. [PMID: 23561533 DOI: 10.1016/j.bpj.2013.01.052] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Revised: 01/21/2013] [Accepted: 01/28/2013] [Indexed: 01/08/2023] Open
Abstract
Recent advances in fluorescence microscopy have enabled high-resolution imaging and tracking of single proteins and biomolecules in cells. To achieve high spatial resolutions in the nanometer range, bright and photostable fluorescent probes are critically required. From this view, there is a strong need for development of advanced fluorescent probes with molecular-scale dimensions for fluorescence imaging. Polymer-based dendrimer nanoconjugates hold strong potential to serve as versatile fluorescent probes due to an intrinsic capacity for tailored spectral properties such as brightness and emission wavelength. In this work, we report a new, to our knowledge, class of molecular probes based on dye-conjugated dendrimers for fluorescence imaging and single-molecule fluorescence microscopy. We engineered fluorescent dendritic nanoprobes (FDNs) to contain multiple organic dyes and reactive groups for target-specific biomolecule labeling. The photophysical properties of dye-conjugated FDNs (Cy5-FDNs and Cy3-FDNs) were characterized using single-molecule fluorescence microscopy, which revealed greatly enhanced photostability, increased probe brightness, and improved localization precision in high-resolution fluorescence imaging compared to single organic dyes. As proof-of-principle demonstration, Cy5-FDNs were used to assay single-molecule nucleic acid hybridization and for immunofluorescence imaging of microtubules in cytoskeletal networks. In addition, Cy5-FDNs were used as reporter probes in a single-molecule protein pull-down assay to characterize antibody binding and target protein capture. In all cases, the photophysical properties of FDNs resulted in enhanced fluorescence imaging via improved brightness and/or photostability.
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Zheng YB, Kiraly B, Weiss PS, Huang TJ. Molecular plasmonics for biology and nanomedicine. Nanomedicine (Lond) 2012; 7:751-70. [PMID: 22630155 DOI: 10.2217/nnm.12.30] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The optical excitation of surface plasmons in metal nanoparticles leads to nanoscale spatial confinement of electromagnetic fields. The confined electromagnetic fields can generate intense, localized thermal energy and large near-field optical forces. The interaction between these effects and nearby molecules has led to the emerging field known as molecular plasmonics. Recent advances in molecular plasmonics have enabled novel optical materials and devices with applications in biology and nanomedicine. In this article, we categorize three main types of interactions between molecules and surface plasmons: optical, thermal and mechanical. Within the scope of each type of interaction, we will review applications of molecular plasmonics in biology and nanomedicine. We include a wide range of applications that involve sensing, spectral analysis, imaging, delivery, manipulation and heating of molecules, biomolecules or cells using plasmonic effects. We also briefly describe the physical principles of molecular plasmonics and progress in the nanofabrication, surface functionalization and bioconjugation of metal nanoparticles.
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Affiliation(s)
- Yue Bing Zheng
- California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA
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Estrada LC, Gratton E. Spectroscopic properties of gold nanoparticles at the single-particle level in biological environments. Chemphyschem 2012; 13:1087-92. [PMID: 22298327 PMCID: PMC4245151 DOI: 10.1002/cphc.201100771] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 01/13/2012] [Indexed: 11/10/2022]
Abstract
Labeling cells and tissues with fluorescent probes, such as organic dyes and quantum dots (Qdots) is a widespread and successful technique for studying molecular dynamics both in vitro and in vivo. However, those probes usually suffer from undesirable photophysical/photochemical processes, such as blinking and photobleaching, limiting their utilization. The main challenges in fluorescent probe design are to improve their absorption/emission properties, and to provide higher stability against photobleaching. In the last few years, metallic nanoparticles (NPs) of various sizes, shapes, and compositions have been used as a new alternative for cellular microscopy. This is in part because-unlike common organic dyes and Qdots-metallic NPs do not bleach or blink upon continuous illumination, are extremely stable, very bright, and their luminescence spans over the visible spectrum. These characteristics make them attractive contrast agents for cell imaging both in vitro and in vivo. For these reasons, the emission of metallic NPs in bulk solutions has already been extensively characterized. In contrast with bulk experiments, where billions of molecules are measured simultaneously, single-particle techniques allow the observation of characteristics and dynamical processes otherwise hidden in the measured average. A full understanding of the photophysical properties of the NPs is critical when they are used for single-molecule applications. Photophysical processes can be a source of artifacts if they are not interpreted accordingly, and thus a careful characterization of these labels at the single-particle level became crucial for the correct interpretation of the experimental results. Herein, we study some of their unique optical properties at the single-particle level and show examples that illustrate their intrinsic heterogeneity when used in biological environments.
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Affiliation(s)
- Laura C. Estrada
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, USA, 3311 Natural Sciences II, Irvine, CA 92697-2715, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Biomedical Engineering Department, University of California, Irvine, USA, 3311 Natural Sciences II, Irvine, CA 92697-2715, USA
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Estrada LC, Roberti MJ, Simoncelli S, Levi V, Aramendía PF, Martínez OE. Detection of Low Quantum Yield Fluorophores and Improved Imaging Times Using Metallic Nanoparticles. J Phys Chem B 2012; 116:2306-13. [DOI: 10.1021/jp209467t] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Laura C. Estrada
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - M. Julia Roberti
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - Sabrina Simoncelli
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - Valeria Levi
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - Pedro F. Aramendía
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - Oscar E. Martínez
- Departamento
de Física, ‡INQUIMAE-Departamento de Química Inorgánica, Analítica
y Química Física, and §Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
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