FLUORESCENCE ENERGY-TRANSFER FROM FLUORESCEIN TO TETRAMETHYLRHODAMINECOVALENTLY BOUND TO THE SURFACE OF POLYSTYRENE LATEX-PARTICLES

Steady-state fluorescence energy transfer experiments have been carrie d out with fluorescein (donor) and tetramethylrhodamine (acceptor) cov alently bound onto the surface of amino functionalized polystyrene lat ex microspheres. 5-Carboxyfluorescein-NHS and 6-carboxytetramethylrhod amine-NHS ester were used to synthesize donor-labeled particles and ac ceptor-labeled particles respectively, as well as donor-acceptor-label ed particles. Some changes in the spectroscopic characteristics of the dyes after their covalent binding onto the PS latex were observed. A theoretical model describing a random distribution of dyes onto the su rface of a sphere corroborates well the experimental energy transfer r esults.