Fabrication of a novel fluorescent material by conjugation of Q-dots with particles

We prepared ZnS:Mn²⁺ nanocrystal-particle complexes and YAG:Ce³⁺ nanocrystal-particle complexes. In addition to the improved dispersion-stability, conjugation of Q-dots with particles enabled us to control the fluorescent properties. The fluorescent intensity increased with increasing the number of incorporated ZnS:Mn²⁺ nanocrystals and the intensity was also enhanced by aging after conjugation. Since YAG:Ce³⁺ nanocrystals have around 30nm in diameter, it was not so easy to assembly them into NAG particles. We could obtain YAG:Ce³⁺ nanocrystal-particle complexes by using negatively-charged NAGCOOH particles. This is because the electrostatic attraction works between the NAGCOOH particles and positively-charged YAG:Ce³⁺ nanocrystals. Although YAG:Ce ³⁺ nanocrystals were apt to aggregate, the obtained complexes were well dispersed even in an aqueous solution containing 100mM NaCl.