A detection system for microfluidic chips based on epifluorescence videomicroscopy and its analytical potentials

An epifluorescence videomicroscopy system with a light-emitting diode as an excitation source and a charge-coupled device matrix as a radiation detector was developed and studied. The system was used for studying mass transfer in microchannels of single- and two-phase systems. It was shown that the developed detection system is suitable for studying mass transfer on a microchip. A one-dimensional physical and mathematical model was developed for mixing processes on a chip. A comparative analysis of experimental results and model concepts demonstrated the diffusion nature of the fluid flow mixing processes. Mass transfer in the two-phase water-octanol system was studied. Dye concentration profiles in a two-phase flow were recorded depending on the time of phase contact. The diffusion nature of mass transfer in the two-phase system was found.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 4, 2005, pp. 357–366.Original Russian Text Copyright © 2005 by Slyadnev, Kazakov, Shcherbaeva, Ganeev, Moskvin, Zolotov.