COLOR COATED LAYER-BY-LAYER MICROCAPSULES SERVING AS COMBINATORY ANALYSIS LIBRARIES AND AS SPECIFIC OPTICAL SENSORS

摘要

Monodisperse colloids were coated with polyelectrolytes by means of the layer-by-layer method. The template cores can remain inside or can be dissolved. Different fluorescent dyes are covalently bound in a defined amount to the polyelectrolytes. The amount of dye is controlled by varying the label content or by the Co deposition of unlabeled polymers. Different dye layers are separated from one another by intermediate layers thereby suppressing unwanted interactions. Conversely, a FRET signal can be generated between suitable dye pairs situated at short distances (0 - 6 nm) from one another. This signal can be controlled independent of the dye concentration by the number of intermediate layers. The capsule coding is read out by the variation in the excitation wavelength and emission wavelength. Macromolecules can be immobilized inside the capsules and extract complementary substances out of solutions. Particles coated in such a manner or hollow capsules can be used as sensors after inserting a sensitive intermediate layer. Changes in the size/structure of the intermediate layer can be detected either by FRET between adjacent, labeled polyelectrolyte layers or by the self-quenching/aggregate fluorescence of dyes in the sensitive layer.