Single Molecule Spectroscopy and Photophysics in Microdroplets:
Staff Scientist
Laser Spectroscopy and Microinstrumentation Group
Oak Ridge National Laboratory
(P) 423/574-4923
e-mail barnesmd1@ornl.gov
B. S. (Chemistry), California State University, Sonoma, 1985
Ph. D. (Chemistry), Rice University, Houston Texas, 1991
As part of Mike Ramsey’s group at ORNL, research in our subgroup focuses on ultrasensitive (single-molecule) fluorescence analysis and photophysics in liquid microdroplets. Some examples of recent work include: single-molecule manipulation and analysis of ultradilute solutions with 1-µm diam. water droplets
, probing single molecules on the surface of spherical microcavities, fluorescence imaging of single molecules in polymer microspheres, and examining material properties of novel polymer alloy and composite microparticles with an eye towards sensor and photonics applications.Collaborators:
Steve Hill
Kin Ng
Past and Current Associates:
Noah Lermer (1995 — 1998)e-mail:
Chung-yi Kung (1994 — 1998)e-mail:
Kerry McNamara (1998)e-mail KerryMc357@aol.com
Don Noide-mail noiddw@ornl.gov
Joshua Otaigbee-mail otaigbe@iastate.edu
Publications
M. D. Barnes, K. C. Ng, K. P. McNamara, C-Y. Kung, J. M. Ramsey and S. C. Hill, "Fluorescence imaging of single molecules in polymer microspheres," accepted for publication in Bioimaging (Dec. 23, 1998).
M. D. Barnes, K. C. Ng, K. Runge, B. G. Sumpter, and D. W. Noid, "Molecular weight and size-directed formation of axi-symmetric nanostructures in polymer blend microparticles," submitted for publication in Journal of Physical Chemistry B (Sept. 25, 1998).
M. D. Barnes, C-Y. Kung, K. Fukui, B. G. Sumpter, D. W. Noid, and J. Otaigbe, "Homogeneous polymer-blend microspheres with tunable refractive index," accepted for publication in Optics Letters (Sept. 25, 1998).
<p>C-Y. Kung, M. D. Barnes, N. Lermer, W. B. Whitten, and J. M. Ramsey, "Single-molecule analysis of ultradilute solutions using guided streams of 1-µm water droplets," Applied Optics in press ( accepted Sept. 28, 1998)
K. Runge, B. G. Sumpter, D. W. Noid, and M. D. Barnes, "Chemical Potential and Symmetry Properties for Excess Electrons on Polymer Nanoparticles: Quantum Drops," Chemical Physics Letters 299 352-357 (1999).
K. Runge, B. G. Sumpter, D. W. Noid, and M. D. Barnes, "Prediction of Quantum Dot-like behavior in Polymer Nanoparticles: Quantum Drops," Journal of Chemical Physics 110, 594-597 (1999).
K. Fukui, B. G. Sumpter, M. D. Barnes, D. W. Noid, and J. U. Otaigbe, "Molecular dynamics simulation of the thermal properties of nanoscale polymer particles," Macromolecular Theory and Simulation in press (accepted September 10, 1998).
C-Y. Kung, M. D. Barnes, B. G. Sumpter, D. W. Noid, and J. Otaigbe, "Production of Monodsisperse Polymer Nanoparticles from Solution," Polymer Preprints
39 (2), 610 (1998).R. W. Shaw, W. B. Whitten, M. D. Barnes, and J. M. Ramsey, "Time-Domain Observation of Optical Pulse Propagation in Whispering Gallery Modes of Glass Spheres," Optics Letters 23, 1301-1303 (1998).
S. C. Hill, M. D. Barnes, N. Lermer, W. B. Whitten, and J. M. Ramsey, "Simulation of single-molecule photocount statistics in microdroplets," Analytical Chemistry 70, 2964-2971 (1998).
N. Lermer, M. D. Barnes, C-Y. Kung, W. B. Whitten, and J. M. Ramsey, "Spatial photoselection of single molecules on the surface of spherical microcavities," Optics Letters 23, 951-953 (1998).
C-Y. Kung, M. D. Barnes, N. Lermer, W. B. Whitten, and J. M. Ramsey, "Confinement and manipulation of individual molecules in attoliter volumes," Analytical Chemistry 70, 658 - 661 (1998)
S. C. Hill, M. D. Barnes, W. B. Whitten, and J. M. Ramsey, "Modeling Fluorescence Collection from Single Molecules in Microspheres: Effects of Position, Orientation and Frequency," Applied Optics, 35, 6278 (1996).
M. D. Barnes, C-Y Kung, W. B. Whitten, J. M. Ramsey, S. Arnold, and S. Holler, "Fluorescence of Oriented Molecules in a Microcavity," Physical Review Letters, 76, 3931 (1996).
M. D. Barnes, C-Y Kung, W. B. Whitten, J. M. Ramsey and S. Arnold, "Molecular Fluorescence in a Microcavity: Solvation Dynamics and Single Molecule Detection," in Optical Processes in Microcavities, R. K. Chang and A. J. Campillo, ed., Advanced Series in Applied Physics (Vol. 3), Chapter 4, World Scientific, Singapore (1996).
M. D. Barnes, W. B. Whitten, and J. M. Ramsey, "Detecting Single Molecules in Liquids," Analytical Chemistry 67, 418A (1995).
M. D. Barnes, W. B. Whitten, and J. M. Ramsey, "Probing femtosecond dynamics in solution on a picosecond time scale: Cavity enhancement of spontaneous emission rates in microdroplets," Chemical Physics Letters 227, 628 (1994).
M. D. Barnes, W. B. Whitten, and J. M. Ramsey, "Enhanced Fluorescence Yields Through Cavity-QED Effects in Microdroplets," Journal of the Optical Society of America B 11, 1297 (1994).
M. D. Barnes, P. R. Brooks, R. F. Curl, and B. R. Johnson, "Probing Chemical Reactions: Evidence for Exploration of an Excited State Potential Energy Surface at Thermal Energies," Science 261, 1434 - 1436 (1993).
M. D. Barnes, K. C. Ng, W. B. Whitten, and J. M. Ramsey, "Detection of Single Rhodamine 6G Molecules in Levitated Microdroplets," Analytical Chemistry 65, 2360 (1993).