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Long Y, Zhang LF, Zhang Y, Zhang CY. Single Quantum Dot Based Nanosensor for Renin Assay. Anal Chem 2012; 84:8846-52. [DOI: 10.1021/ac302284s] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yi Long
- Single-Molecule Detection and
Imaging Laboratory, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Guangdong 518055, China
| | - Ling-fei Zhang
- Single-Molecule Detection and
Imaging Laboratory, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Guangdong 518055, China
- Weihai Municipal Center for Disease Control and Prevention, Shandong
264200, China
| | - Yan Zhang
- Single-Molecule Detection and
Imaging Laboratory, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Guangdong 518055, China
| | - Chun-yang Zhang
- Single-Molecule Detection and
Imaging Laboratory, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Guangdong 518055, China
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2
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Chou CK, Jing N, Yamaguchi H, Tsou PH, Lee HH, Chen CT, Wang YN, Hong S, Su C, Kameoka J, Hung MC. High speed digital protein interaction analysis using microfluidic single molecule detection system. LAB ON A CHIP 2010; 10:1793-8. [PMID: 20498894 PMCID: PMC2919816 DOI: 10.1039/c002937h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The understanding of protein interaction dynamics is important for signal transduction research but current available techniques prove difficult in addressing this issue. Thus, using the microfluidic approach, we developed a digital protein analytical platform and methodology named MAPS (Microfluidic system Analyzing Protein in Single complex) that can measure the amount of target proteins and protein complexes at the digitally single molecule resolution. By counting protein events individually, this system can provide rough protein interaction ratios which will be critical for understanding signal transduction dynamics. In addition, this system only requires less than an hour to characterize the target protein sample, which is much quicker than conventional approaches. As a proof of concept, we have determined the interaction ratios of oncogenic signaling protein complexes EGFR/Src and EGFR/STAT3 before and after EGF ligand stimulation. To the best of our knowledge, this is the first time that the interaction ratio between EGFR and its downstream proteins has been characterized. The information from MAPS will be critical for the study of protein signal transduction quantitation and dynamics.
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Affiliation(s)
- Chao-Kai Chou
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Cancer Biology Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Texas, USA
| | - Nan Jing
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Hirohito Yamaguchi
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Pei-Hsiang Tsou
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Heng-Huan Lee
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Cancer Biology Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Texas, USA
| | - Chun-Te Chen
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Cancer Biology Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Texas, USA
| | - Ying-Nai Wang
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
| | - Sungmin Hong
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Chin Su
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Jun Kameoka
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA
| | - Mien-Chie Hung
- Department of Molecular and Cellular Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
- Cancer Biology Program, Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Texas, USA
- Center for Molecular Medicine and Graduate Institute of Cancer Biology, China Medical University and Hospital, Taichung, Taiwan
- Department of Biotechnology, Asia University, Taichung, Taiwan
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3
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Xu Y, Takai M, Ishihara K. Phospholipid Polymer Biointerfaces for Lab-on-a-Chip Devices. Ann Biomed Eng 2010; 38:1938-53. [DOI: 10.1007/s10439-010-0025-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 03/22/2010] [Indexed: 01/09/2023]
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4
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Fu Y, Zhang J, Lakowicz JR. Highly efficient detection of single fluorophores in blood serum samples with high autofluorescence. Photochem Photobiol 2009; 85:646-51. [PMID: 19192209 PMCID: PMC2755222 DOI: 10.1111/j.1751-1097.2008.00500.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single molecule detection (SMD) is usually performed on surface-immobilized molecules with diffraction-limited observation volumes, typically with confocal optics to suppress background from the sample and instrument. In this paper we consider the more difficult task of detecting single fluorophores in the presence of a substantial fluorescence background. We determined that for a readily accessible macroscopic observation volume of 1 pL that the background from undiluted blood serum was approximately equal to 2700 Cy5 molecules, and the background from whole blood equal to about 14 000 Cy5 molecules in whole blood. These high backgrounds appear to preclude the possibility of SMD of Cy5 molecules. However, we show that the signal-to-noise ratio (SNR) in high background samples can be increased dramatically by reduction of the observed volume. We were able to detect single surface-bound Cy5-labeled DNA (Cy5-DNA) oligomers in diluted blood serum with an SNR near 40. We also examined freely diffusing Cy5-DNA in blood serum. The data showed that single Cy5-DNA molecules could be detected even in the undiluted serum. We further investigated the SNR on silver island films. We found that the fluorescence signal was greatly enhanced in the presence of metallic nanostructures showing a larger SNR in the application tested. These results suggest the possibility of clinical assays based on SMD in blood serum and possibly whole blood. Increased SNR near metallic nanostructure could probably overcome the need for diffraction-limited volumes and enhance our ability to do in situ SMD.
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Affiliation(s)
- Yi Fu
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD
| | - Jian Zhang
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD
| | - Joseph R. Lakowicz
- Department of Biochemistry and Molecular Biology, Center for Fluorescence Spectroscopy, University of Maryland School of Medicine, Baltimore, MD
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5
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Li L, Tian X, Zou G, Shi Z, Zhang X, Jin W. Quantitative Counting of Single Fluorescent Molecules by Combined Electrochemical Adsorption Accumulation and Total Internal Reflection Fluorescence Microscopy. Anal Chem 2008; 80:3999-4006. [DOI: 10.1021/ac702534h] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lu Li
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Xinzhe Tian
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Guizheng Zou
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Zhikun Shi
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Xiaoli Zhang
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
| | - Wenrui Jin
- School of Chemistry and Chemical Engineering and Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Shandong University, Jinan 250100, China
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7
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Wang L, Xu G, Shi Z, Jiang W, Jin W. Quantification of protein based on single-molecule counting by total internal reflection fluorescence microscopy with adsorption equilibrium. Anal Chim Acta 2007; 590:104-9. [PMID: 17416229 DOI: 10.1016/j.aca.2007.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Revised: 03/03/2007] [Accepted: 03/08/2007] [Indexed: 11/17/2022]
Abstract
We developed a sensitive single-molecule imaging method for quantification of protein by total internal reflection fluorescence microscopy with adsorption equilibrium. In this method, the adsorption equilibrium of protein was achieved between solution and glass substrate. Then, fluorescence images of protein molecules in a evanescent wave field were taken by a highly sensitive electron multiplying charge coupled device. Finally, the number of fluorescent spots corresponding to the protein molecules in the images was counted. Alexa Fluor 488-labeled goat anti-rat IgG(H+L) was chosen as the model protein. The spot number showed an excellent linear relationship with protein concentration. The concentration linear range was 5.4 x 10(-11) to 8.1 x 10(-10) mol L(-1).
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Affiliation(s)
- Lei Wang
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, PR China
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8
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Abstract
Advances in technology have allowed chemical sampling with high spatial resolution and the manipulation and measurement of individual molecules. Adaptation of these approaches to lab-on-a-chip formats is providing a new class of research tools for the investigation of biochemistry and life processes.
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Affiliation(s)
- Harold Craighead
- Applied and Engineering Physics, 205 Clark Hall, Cornell University, Ithaca, New York 14853, USA.
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9
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Preparation of mono-dispersed mixed metal oxide micro hollow spheres by homogeneous precipitation in a micro precipitator. POWDER TECHNOL 2005. [DOI: 10.1016/j.powtec.2005.03.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Barnes MD, Mehta A, Kumar P, Sumpter BG, Noid DW. Confinement effects on the structure and dynamics of polymer systems from the mesoscale to the nanoscale. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/polb.20460] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Böhmer M, Enderlein J. Fluorescence spectroscopy of single molecules under ambient conditions: methodology and technology. Chemphyschem 2003; 4:793-808. [PMID: 12961976 DOI: 10.1002/cphc.200200565] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
This review presents an overview of the fluorescence detection and spectroscopy of single molecules (SMS) in liquids and on surfaces under ambient conditions. The various techniques of SMS, such as confocal epifluorescence detection and wide-field imaging are presented and discussed, together with the different methods of data analysis such as fluorescence correlation spectroscopy and burst-by-burst analysis. Selected applications of the various techniques in physics, chemistry, and biology are described.
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Affiliation(s)
- Martin Böhmer
- IBI-1, Forschungszentrum Jülich 52425 Jülich, Germany
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12
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Feng J, Shan G, Hammock BD, Kennedy IM. Fluorescence quenching competitive immunoassay in micro droplets. Biosens Bioelectron 2003; 18:1055-63. [PMID: 12782469 DOI: 10.1016/s0956-5663(02)00218-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A fluorescence quenching competitive immunoassay in micro droplets was applied to the sensitive detection of the pyrethroid insecticide, esfenvalerate. Laser induced fluorescence from rhodamine dye was used as a marker. The competitive immunoreaction was performed in micro droplets generated by a vibrating orifice aerosol generator system with a 10-microm diameter orifice. Fluorescence that was emitted from the droplets was detected by a 1/8 m imaging spectrograph with a 512 x 512 thermoelectrically cooled, charged-coupled device camera. The conjugate of esfenvalerate with rhodamine exhibited similar fluorescence to that of pure rhodamine 6G. When anti-esfenvalerate antibodies were added to the droplets, the fluorescence decreased. The reduction in emission was due to a strong quenching effect that arises from the interaction between the protein and rhodamine molecules following the antigen-antibody reaction. When a sample of esfenvalerate was added to the droplets, the release of the conjugated rhodamine from the antigen-antibody complex allowed the fluorescence signal to recover. An assay in a picoliter droplet sample was shown to enable detection down to approximately 0.1 nM. A very small mass of analyte could be detected with this method. A sample of river water was used to gauge the impact of matrix effects and was shown to give rise to negligible interference with the immunoassay.
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Affiliation(s)
- Jun Feng
- Department of Mechanical and Aeronautical Engineering, University of California, Davis, CA 95616, USA
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13
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Thorsen T, Roberts RW, Arnold FH, Quake SR. Dynamic pattern formation in a vesicle-generating microfluidic device. PHYSICAL REVIEW LETTERS 2001; 86:4163-6. [PMID: 11328121 DOI: 10.1103/physrevlett.86.4163] [Citation(s) in RCA: 1016] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2001] [Indexed: 05/19/2023]
Abstract
Spatiotemporal pattern formation occurs in a variety of nonequilibrium physical and chemical systems. Here we show that a microfluidic device designed to produce reverse micelles can generate complex, ordered patterns as it is continuously operated far from thermodynamic equilibrium. Flow in a microfluidic system is usually simple-viscous effects dominate and the low Reynolds number leads to laminar flow. Self-assembly of the vesicles into patterns depends on channel geometry and relative fluid pressures, enabling the production of motifs ranging from monodisperse droplets to helices and ribbons.
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Affiliation(s)
- T Thorsen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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14
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Generation, Characterization, and Modeling of Polymer Micro- and Nano-Particles. POLYMER PHYSICS AND ENGINEERING 2001. [DOI: 10.1007/3-540-44484-x_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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15
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16
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Ball JC, Lumpp JK, Daunert S, Bachas LG. Effect of Fabrication Factors on Performance of Screen-Printed/Laser Micromachined Electrochemical Nanovials. ELECTROANAL 2000. [DOI: 10.1002/1521-4109(200005)12:9<685::aid-elan685>3.0.co;2-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Noid D, Fukui K, Sumpter B, Yang C, Tuzun R. Time-averaged normal coordinate analysis of polymer particles and crystals. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(99)01152-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Fukui K, Sumpter BG, Noid DW, Yang C, Tuzun RE. Large-Scale Normal Coordinate Analysis of Macromolecular Systems: Thermal Properties of Polymer Particles and Crystals†. J Phys Chem B 2000. [DOI: 10.1021/jp993149+] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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19
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Ford J, Sumpter B, Noid D, Barnes M. Observation of size oscillations in poly(ethylene) glycol/electrolyte composite microparticles. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(99)01332-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Gensch T, Hofkens J, Herrmann A, Tsuda K, Verheijen W, Vosch T, Christ T, Basché T, Müllen K, De Schryver F. Fluoreszenzuntersuchungen einzelner Dendrimermoleküle mit mehreren Chromophoren. Angew Chem Int Ed Engl 1999. [DOI: 10.1002/(sici)1521-3757(19991216)111:24<3970::aid-ange3970>3.0.co;2-i] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Fukui K, Sumpter B, Barnes M, Noid D. Molecular dynamics studies of the structure and properties of polymer nano-particles. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s1089-3156(99)00010-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Fukui K, Sumpter BG, Barnes MD, Noid DW. Molecular Dynamics Simulation of Polymer Fine Particles. Physical and Mechanical Properties. Polym J 1999. [DOI: 10.1295/polymj.31.664] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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23
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Barnes MD, Ng KC, McNamara KP, Kung CY, Ramsey JM, Hill SC. Fluorescence imaging of single molecules in polymer microspheres. CYTOMETRY 1999; 36:169-75. [PMID: 10404964 DOI: 10.1002/(sici)1097-0320(19990701)36:3<169::aid-cyto4>3.0.co;2-i] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report on far-field fluorescence imaging of single molecules in spherical polymer microparticles produced from solution by using microdroplet techniques. The fluorescence photobleaching quantum yields of rhodamine 6G in a common water-soluble polymer (polyvinyl alcohol) are at least five times smaller, corresponding to proportionally larger average fluorescence signals, than those in ethanolic solvents. This allows for acquisition of multiple images from a single molecule on a time scale of several minutes. We also show that fluorescent images of single molecules in microspheres can be calculated from semiclassic electrodynamics, which may ultimately be useful in retrieving dynamical information from experimental images.
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Affiliation(s)
- M D Barnes
- Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Tennessee 37831-6142, USA
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24
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Fukui K, Sumpter BG, Runge K, Kung CY, Barnes MD, Noid DW. Collision dynamics and surface wetting of nano-scale polymer particles on substrates. Chem Phys 1999. [DOI: 10.1016/s0301-0104(99)00131-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Kung CY, Barnes MD, Lermer N, Whitten WB, Ramsey JM. Single-molecule analysis of ultradilute solutions with guided streams of 1--microm water droplets. APPLIED OPTICS 1999; 38:1481-1487. [PMID: 18305770 DOI: 10.1364/ao.38.001481] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We describe instrumentation for real-time detection of single-molecule fluorescence in guided streams of 1-microm (nominal) water droplets. In this technique, target molecules were confined to droplets whose volumes were comparable with illumination volumes in diffraction-limited fluorescence microscopy and guided to the waist of a cw probe laser with an electrostatic potential. Concentration detection limits for Rhodamine 6G in water were determined to be approximately 1 fM, roughly 3 orders of magnitude lower than corresponding limits determined recently with diffraction-limited microscopy techniques for a chemical separation of similar dyes. In addition to its utility as a vehicle for probing single molecules, instrumentation for producing and focusing stable streams of 1-2-microm-diameter droplets may have other important analytical applications as well.
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Affiliation(s)
- C Y Kung
- Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, Tennessee 37831-6142, USA
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26
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Chiu DT, Wilson CF, Ryttsén F, Strömberg A, Farre C, Karlsson A, Nordholm S, Gaggar A, Modi BP, Moscho A, Garza-López RA, Orwar O, Zare RN. Chemical transformations in individual ultrasmall biomimetic containers. Science 1999; 283:1892-5. [PMID: 10082457 DOI: 10.1126/science.283.5409.1892] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Individual phospholipid vesicles, 1 to 5 micrometers in diameter, containing a single reagent or a complete reaction system, were immobilized with an infrared laser optical trap or by adhesion to modified borosilicate glass surfaces. Chemical transformations were initiated either by electroporation or by electrofusion, in each case through application of a short (10-microsecond), intense (20 to 50 kilovolts per centimeter) electric pulse delivered across ultramicroelectrodes. Product formation was monitored by far-field laser fluorescence microscopy. The ultrasmall characteristic of this reaction volume led to rapid diffusional mixing that permits the study of fast chemical kinetics. This technique is also well suited for the study of reaction dynamics of biological molecules within lipid-enclosed nanoenvironments that mimic cell membranes.
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Affiliation(s)
- D T Chiu
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
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27
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Barnes MD, Kung CY, Lermer N, Fukui K, Sumpter BG, Noid DW, Otaigbe JU. Homogeneous polymer blend microparticles with a tunable refractive index. OPTICS LETTERS 1999; 24:121-3. [PMID: 18071427 DOI: 10.1364/ol.24.000121] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We show that homogeneous polymer blend microparticles can be prepared in situ from droplets of dilute solution of codissolved polymers. Provided that the droplet of solution is small enough (<10 mum), solvent evaporation is rapid enough to inhibit phase separation. Thus the polymers that are being mixed need not be miscible, which greatly enhances the applicability of the technique. From analysis of two-dimensional Fraunhofer diffraction (angular scattering) patterns, we show that both the real and the imaginary parts of the refractive index can be tuned by adjustment of the relative weight fractions of polymers in solution.
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