Characterization of luminescent monodisperse microparticles prepared by gamma radiation-initiated polymerization

Fluorescent microparticles have been prepared by gamma radiation-initiated precipitation polymerization of diethylene glycol dimethacrylate monomer with ethyl propionate solvent and fluorescein isothiocyanate isomer-I (FITC) fluorophore. Different FITC concentrations and irradiation conditions were used, and their effect on the particle properties was studied. The samples were characterized by scanning electron microscopy, Raman and photoluminescence spectroscopies. Our results showed that the size of the microspheres is dependent on the composition of the monomer mixture. The uniformity of the microparticles decreases with increasing FITC concentration, relative to the monomer. Changes in the emission spectrum of the FITC were also observed after irradiation. The gamma irradiation-initiated polymerization was found to be a promising and simple technique to prepare luminescent spherical microparticles.