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Calver CF, Lago BA, Schanze KS, Cosa G. Enhancing the photostability of poly(phenylene ethynylene) for single particle studies. Photochem Photobiol Sci 2017; 16:1821-1831. [DOI: 10.1039/c7pp00276a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Enhanced photostability of conjugated polyelectrolytes achieved by using anti-fading agents opens the way for advanced single molecule fluorescence imaging studies.
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Affiliation(s)
- C. F. Calver
- Department of Chemistry and Centre for Self-Assembled Chemical Structures (CSACS/CRMAA)
- McGill University
- Montreal
- Canada
| | - B. A. Lago
- Department of Chemistry and Centre for Self-Assembled Chemical Structures (CSACS/CRMAA)
- McGill University
- Montreal
- Canada
| | - K. S. Schanze
- Department of Chemistry
- University of Texas at San Antonio
- San Antonio
- USA
| | - G. Cosa
- Department of Chemistry and Centre for Self-Assembled Chemical Structures (CSACS/CRMAA)
- McGill University
- Montreal
- Canada
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2
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Calver CF, Liu HW, Cosa G. Exploiting Conjugated Polyelectrolyte Photophysics toward Monitoring Real-Time Lipid Membrane-Surface Interaction Dynamics at the Single-Particle Level. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:11842-11850. [PMID: 25955885 DOI: 10.1021/acs.langmuir.5b00979] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Herein we report the real-time observation of the interaction dynamics between cationic liposomes flowing in solution and a surface-immobilized charged scaffolding formed by the deposition of conjugated polyanion poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene (MPS-PPV) onto 100-nm-diameter SiO2 nanoparticles (NPs). Contact of the freely floating liposomes with the polymer-coated surfaces led to the formation of supported lipid bilayers (SLBs). The interaction of the incoming liposomes with MPS-PPV adsorbed on individual SiO2 nanoparticles promoted the deaggregation of the polymer conformation and led to large emission intensity enhancements. Single-particle total internal reflection fluorescence microscopy studies exploited this phenomenon as a way to monitor the deformation dynamics of liposomes on surface-immobilized NPs. The MPS-PPV emission enhancement (up to 25-fold) reflected on the extent of membrane contact with the surface of the NP and was correlated with the size of the incoming liposome. The time required for the MPS-PPV emission to reach a maximum (ranging from 400 to 1000 ms) revealed the dynamics of membrane deformation and was also correlated with the liposome size. Cryo-TEM experiments complemented these results by yielding a structural view of the process. Immediately following the mixing of liposomes and NPs the majority of NPs had one or more adsorbed liposomes, yet the presence of a fully formed SLB was rare. Prolonged incubation of liposomes and NPs showed completely formed SLBs on all of the NPs, confirming that the liposomes eventually ruptured to form SLBs. We foresee that the single-particle studies we report herein may be readily extended to study membrane dynamics of other lipids including cellular membranes in live cell studies and to monitor the formation of polymer-cushioned SLBs.
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Affiliation(s)
- Christina F Calver
- Department of Chemistry and Centre for Self Assembled Chemical Structures (CSACS/CRMAA), McGill University , 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada
| | - Hsiao-Wei Liu
- Department of Chemistry and Centre for Self Assembled Chemical Structures (CSACS/CRMAA), McGill University , 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada
| | - Gonzalo Cosa
- Department of Chemistry and Centre for Self Assembled Chemical Structures (CSACS/CRMAA), McGill University , 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada
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Darwish GH, Karam P. Nanohybrid conjugated polyelectrolytes: highly photostable and ultrabright nanoparticles. NANOSCALE 2015; 7:15149-15158. [PMID: 26255590 DOI: 10.1039/c5nr03299g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a general and straightforward one-step approach to enhance the photophysical properties of conjugated polyelectrolytes. Upon complexation with an amphiphilic polymer (polyvinylpyrrolidone), an anionic conjugated polyelectrolyte (poly[5-methoxy-2-(3-sulfopropoxy)-1,4-phenylenevinylene]) was prepared into small nanoparticles with exceptional photostability and brightness. The polymer fluorescence intensity was enhanced by 23 -fold and could be easily tuned by changing the order of addition. Single molecule experiments revealed a complete suppression of blinking. In addition, after only losing 18% of the original intensity, a remarkable amount of photons were emitted per particle (∼10(9), on average). This number is many folds greater than popular organic fluorescent dyes. We believe that an intimate contact between the two polymers is shielding the conjugated polyelectrolyte from the destructive photooxidation. The prepared nanohybrid particles will prove instrumental in single particle based fluorescent assays and can serve as a probe for the current state-of-the-art bioimaging fluorescence techniques.
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Affiliation(s)
- Ghinwa H Darwish
- Department of Chemistry, American University of Beirut, P.O. Box 11-0236, Beirut, Lebanon.
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Aebisher D, Bartusik D, Liu Y, Zhao Y, Barahman M, Xu Q, Lyons AM, Greer A. Superhydrophobic photosensitizers. Mechanistic studies of (1)O2 generation in the plastron and solid/liquid droplet interface. J Am Chem Soc 2013; 135:18990-8. [PMID: 24295210 DOI: 10.1021/ja410529q] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We describe here a physical-organic study of the first triphasic superhydrophobic sensitizer for photooxidations in water droplets. Control of synthetic parameters enables the mechanistic study of "borderline" two- and three-phase superhydrophobic sensitizer surfaces where (1)O2 is generated in compartments that are wetted, partially wetted, or remain dry in the plastron (i.e., air layer beneath the droplet). The superhydrophobic surface is synthesized by partially embedding silicon phthalocyanine (Pc) sensitizing particles to specific locations on polydimethylsiloxane (PDMS) posts printed in a square array (1 mm tall posts on 0.5 mm pitch). In the presence of red light and oxygen, singlet oxygen is formed on the superhydrophobic surface and reacts with 9,10-anthracene dipropionate dianion (1) within a freestanding water droplet to produce an endoperoxide in 54-72% yields. Control of the (1)O2 chemistry was achieved by the synthesis of superhydrophobic surfaces enriched with Pc particles either at the PDMS end-tips or at PDMS post bases. Much of the (1)O2 that reacts with anthracene 1 in the droplets was generated by the sensitizer "wetted" at the Pc particle/water droplet interface and gave the highest endoperoxide yields. About 20% of the (1)O2 can be introduced into the droplet from the plastron. The results indicate that the superhydrophobic sensitizer surface offers a unique system to study (1)O2 transfer routes where a balance of gas and liquid contributions of (1)O2 is tunable within the same superhydrophobic surface.
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Affiliation(s)
- David Aebisher
- Department of Natural Sciences, Shorter University , Rome, Georgia 30165, United States
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Hamblin GD, Hariri AA, Carneiro KMM, Lau KL, Cosa G, Sleiman HF. Simple design for DNA nanotubes from a minimal set of unmodified strands: rapid, room-temperature assembly and readily tunable structure. ACS NANO 2013; 7:3022-8. [PMID: 23452006 DOI: 10.1021/nn4006329] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
DNA nanotubes have great potential as nanoscale scaffolds for the organization of materials and the templation of nanowires and as drug delivery vehicles. Current methods for making DNA nanotubes either rely on a tile-based step-growth polymerization mechanism or use a large number of component strands and long annealing times. Step-growth polymerization gives little control over length, is sensitive to stoichiometry, and is slow to generate long products. Here, we present a design strategy for DNA nanotubes that uses an alternative, more controlled growth mechanism, while using just five unmodified component strands and a long enzymatically produced backbone. These tubes form rapidly at room temperature and have numerous, orthogonal sites available for the programmable incorporation of arrays of cargo along their length. As a proof-of-concept, cyanine dyes were organized into two distinct patterns by inclusion into these DNA nanotubes.
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Affiliation(s)
- Graham D Hamblin
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 0B8 Canada
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Marko RA, Liu HW, Ablenas CJ, Ehteshami M, Götte M, Cosa G. Binding kinetics and affinities of heterodimeric versus homodimeric HIV-1 reverse transcriptase on DNA-DNA substrates at the single-molecule level. J Phys Chem B 2013; 117:4560-7. [PMID: 23305243 DOI: 10.1021/jp308674g] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
During viral replication, HIV-1 reverse transcriptase (RT) plays a pivotal role in converting genomic RNA into proviral DNA. While the biologically relevant form of RT is the p66-p51 heterodimer, two recombinant homodimer forms of RT, p66-p66 and p51-p51, are also catalytically active. Here we investigate the binding of the three RT isoforms to a fluorescently labeled 19/50-nucleotide primer/template DNA duplex by exploiting single-molecule protein-induced fluorescence enhancement (SM-PIFE). PIFE, which does not require labeling of the protein, allows us to directly visualize the binding/unbinding of RT to a double-stranded DNA substrate. We provide values for the association and dissociation rate constants of the RT homodimers p66-p66 and p51-p51 with a double-stranded DNA substrate and compare those to the values recorded for the RT heterodimer p66-p51. We also report values for the equilibrium dissociation constant for the three isoforms. Our data reveal great similarities in the intrinsic binding affinities of p66-p51 and p66-p66, with characteristic Kd values in the nanomolar range, much smaller (50-100-fold) than that of p51-p51. Our data also show discrepancies in the association/dissociation dynamics among the three dimeric RT isoforms. Our results further show that the apparent binding affinity of p51-p51 for its DNA substrate is to a great extent time-dependent when compared to that of p66-p66 and p66-p51, and is more likely determined by the dimer dissociation into its constituent monomers rather than the intrinsic binding affinity of dimeric RT.
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Affiliation(s)
- Ryan A Marko
- Department of Chemistry and Center for Self Assembled Chemical Structures (CSACS/CRMAA), McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A 0B8, Canada
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Bao B, Tao N, Yang D, Yuwen L, Weng L, Fan Q, Huang W, Wang L. A controllable approach to development of multi-spectral conjugated polymer nanoparticles with increased emission for cell imaging. Chem Commun (Camb) 2013; 49:10623-5. [DOI: 10.1039/c3cc46605a] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Zhang D, Song C, Deng J, Yang W. Chiral Microspheres Consisting Purely of Optically Active Helical Substituted Polyacetylene: The First Preparation via Precipitation Polymerization and Application in Enantioselective Crystallization. Macromolecules 2012. [DOI: 10.1021/ma301250u] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Dongyue Zhang
- State Key Laboratory of Chemical
Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing
100029, China
| | - Ci Song
- State Key Laboratory of Chemical
Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing
100029, China
| | - Jianping Deng
- State Key Laboratory of Chemical
Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing
100029, China
| | - Wantai Yang
- State Key Laboratory of Chemical
Resource Engineering, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing
100029, China
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Swoboda M, Henig J, Cheng HM, Brugger D, Haltrich D, Plumeré N, Schlierf M. Enzymatic oxygen scavenging for photostability without pH drop in single-molecule experiments. ACS NANO 2012; 6:6364-9. [PMID: 22703450 PMCID: PMC3403312 DOI: 10.1021/nn301895c] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 06/17/2012] [Indexed: 05/18/2023]
Abstract
Over the past years, bottom-up bionanotechnology has been developed as a promising tool for future technological applications. Many of these biomolecule-based assemblies are characterized using various single-molecule techniques that require strict anaerobic conditions. The most common oxygen scavengers for single-molecule experiments are glucose oxidase and catalase (GOC) or protocatechuate dioxygenase (PCD). One of the pitfalls of these systems, however, is the production of carboxylic acids. These acids can result in a significant pH drop over the course of experiments and must thus be compensated by an increased buffer strength. Here, we present pyranose oxidase and catalase (POC) as a novel enzymatic system to perform single-molecule experiments in pH-stable conditions at arbitrary buffer strength. We show that POC keeps the pH stable over hours, while GOC and PCD cause an increasing acidity of the buffer system. We further verify in single-molecule fluorescence experiments that POC performs as good as the common oxygen-scavenging systems, but offers long-term pH stability and more freedom in buffer conditions. This enhanced stability allows the observation of bionanotechnological assemblies in aqueous environments under well-defined conditions for an extended time.
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Affiliation(s)
- Marko Swoboda
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Arnoldstraße 18, 01307 Dresden, Germany
| | - Jörg Henig
- Center for Electrochemical Sciences, CES, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Hsin-Mei Cheng
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Arnoldstraße 18, 01307 Dresden, Germany
| | - Dagmar Brugger
- Food Biotechnology Laboratory, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Dietmar Haltrich
- Food Biotechnology Laboratory, University of Natural Resources and Life Sciences Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Nicolas Plumeré
- Center for Electrochemical Sciences, CES, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
- E-mail: ,
| | - Michael Schlierf
- B CUBE, Center for Molecular Bioengineering, Technische Universität Dresden, Arnoldstraße 18, 01307 Dresden, Germany
- E-mail: ,
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