Abstract
Fluorescence bioimaging is one of the most important technologies for biomedical applications. The most serious problem for the imaging is color fading, phototoxicity, autofluorescence and strong scattering due to the use of short-wavelength excitation light. For solving all of these problems, we propose to use fluorescence under near infrared excitation by using rare-earth doped ceramic nanophoshpors. Surface modification of the particles with biofunctional polymer was applied for dispersion stability, specific interaction with the substances in biosystem and chemical durability. Some demonstrative works of the bioimaging will be also presented.