Fluorescent gel particles in the nanometer range for detection of metabolites in living cells

In this present work a research program that aims at the development of sensor particles based on ratiometric detection of fluorescence from two dyes was embarked on. Such particles can in principle be used to achieve spatially and time resolved measurements of metabolite concentrations in living cells. The dyes are chosen such that the fluorescence of one dye is a function of an analyte concentration whereas the fluorescence of the other dye is independent of variations in the medium. Methods have been investigated for synthesizing such particles based on crosslinked polyacrylamide in inverse micelles in oil microemulsions. Typical sizes of the particles are tens of nanometers. Characterization methods for such particles based on size exclusion chromatography, photon correlation spectroscopy, scanning electron microscopy, and atomic force microscopy have been developed. The stability of the sensor particles and their potential as an analytical tool will be discussed. Copyright (c) 2006 John Wiley & Sons, Ltd.