Figure 1.

A) Schematic of the experimental setup used to excite and collect signals from particles encapsulated within microdroplets. B) With fluorescence correlation spectroscopy, which used point detection with an avalanche photodiode (APD), the confocal probe volume was placed at the center of the water droplet to detect burst events from the contained particles, thus measuring the diffusion time and size of the particles. C) For particle tracking, which used imaging with a sensitive CCD camera, each particle was tracked individually and the associated Δx and Δy values were recorded and used to calculate the diffusion time for each particle in the droplet.