Single Molecule Spectroscopy and Photophysics in Microdroplets:

1-µm diam. water droplets
Brief description: We have developed instrumentation for probing single molecules in confined to water droplets (1-µm diam.) whose volumes are comparable to typical illumination volumes in diffraction-limited microscopy. However, unlike fluorescence microscopy on freely diffusing molecules in solution, the molecules being probed in our technique are confined to the droplet which can be manipulated on macroscopic length scales.






Apparatus schematic





SMD data: 26 fM R6G probed in 1-µm diameter water droplets. The abscissa is the droplet number, and the ordinate is the number of fluorescence and background counts integrated during the 5 msec droplet transit time.SMD