Caged-Fluorescence Imaging

Like traditional dye injection techniques, the caged-fluorescence technique allows optical extraction of information about scalar transport in microfluidic systems. A caged-dye is homogeneously distributed throughout a buffer solution and then injected into a microfluidic system. To obtain concentration information, the buffer was excited to fluoresce through two independent laser excitation events: 1) an uncaging of the dye and 2) an application of fluorescence exciting illumination. A time sequence of independent realizations is then obtained and processed. The caged-fluorescence method is especially useful in flow field interrogation, as the technique essentially allows for an “optical injection” of a well-defined sample plug. This eliminates any initial sample distortion that would be created through the physical injection of dye by hydrodynamic and electrokinetic means.

References:
  • A.E. Herr, J.I. Molho, J.G. Santiago, M.G. Mungal, T.W. Kenny, M.G. Garguilo, "Electroosmotic Capillary Flow with Nonuniform Zeta-Potential," Analytical Chemistry, Vol.72, No.5, March 1, 2000, pp.1053-1057.
  • Paul, P. H.; Garguilo, M. G.; and Rakestraw, D. J. Analytical Chemistry, 1998, 70, 2459-2467.
  • Lempert, W.R.; Magee, K.; Ronney, P.; Gee, K.R.; Haugland, R.P. Experiments in Fluids, 1995, 18, 249-257.

aeh
07.20.03