Imaging and Time-Resolved Spectroscopy of Single Molecules at an Interface

• Published in: Science (American Association for the Advancement of Science) Vol. 272; no. 5259; pp. 255 - 258
• Main Authors: Macklin, J. J., Trautman, J. K., Harris, T. D., Brus, L. E.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 12.04.1996; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Atomic and molecular physics; Charge separation; Climate; Dyes; Emission spectra; Exact sciences and technology; Fluorescence; Fluorescence and phosphorescence spectra; Fluorescence and phosphorescence; radiationless transitions, quenching (intersystem crossing, internal conversion); Lasers; Molecular properties and interactions with photons; Molecular spectra; Molecular spectroscopy; Molecules; Optics; Physics; Pollutant emissions; Spectroscopy; Spectrum analysis; Wavelengths; Cyanine dyes; Time resolution; Lifetime; Optical microscopy; Molecular orientation; Gas solid interface; Fluorescence; Air; Experimental study; Polymers; Organic compounds
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.272.5259.255

Far-field microscopy was used to noninvasively measure the room-temperature optical properties of single dye molecules located on a polymer-air interface. Shifts in the fluorescence spectrum, due to perturbation by the locally varying molecular environment, and the orientation of the transition dipole moment were correlated to variation in the excited-state lifetime. The lifetime dependence on spectral shift is argued to result from the frequency dependence of the spontaneous emission rate; the lifetime dependence on dipole orientation was found to be a consequence of the electromagnetic boundary conditions on the fluorescent radiation at the polymer-air interface.