Tagging of avidin immobilized beads with biotinylated YAG:Ce3+ nanocrystal phosphor.

YAG:Ce3+ nanoparticles 9.5+/-1.2 nm in diameter have been synthesized from aluminium isopropoxide and acetates of yttrium and cerium in 1,4-butanediol (1,4-BD) by autoclave treatment at 300 degrees C for 2 h. After replacing 1,4-BD by ultrapure water, NH2 groups were introduced on the surface of YAG:Ce3+ nanoparticles by addition of 3-aminopropyltrimethoxysilane then biotinylation with sulfo-NHS-LC-biotin. We demonstrated that avidin immobilized beads are tagged by biotinylated YAG:Ce3+ nanoparticles by the selective avidin-biotin interaction, furnishing a green fluorescent image on excitation with blue light. This result indicates that YAG:Ce3+ nanoparticle phosphors have much potential in biological applications.