Increase in the fluorescence intensity of ZnO nanoparticle by laser irradiation

We increased fluorescence intensity of ZnO nanoparticles by irradiation of laser to nanoparticles in solvent. The intensity of laser-irradiated nanoparticles became 1.4 times larger than that of non-irradiated one. The ZnO nanoparticles were synthesized by precipitation method. The laser for irradiation to ZnO nanoparticles was He-Cd cw laser. It was found that the average particle size was slightly increased during laser irradiation by red-shifted absorbance onset. These highly-fluorescent nanoparticles in solvent are useful for biomedical field such as biological imaging. (C) 2008 Elsevier B.V. All rights reserved.