Aim: To synthesize biocompatible nanoparticles of FAp co-doped with Yb/Er
and Nd/Yb for bioimaging applications.
Methods: Yb/Er FAp and Nd/Yb FAp was synthesized using microwave assisted wet precipitation
and hydrothermal method respectively. Trisodium citrate was used as an organic
modifier for the synthesis and then subjected to heat treatment for optical activation. For
optical studies, Yb/Er FAp system was excited at 980 nm and Nd/Yb FAp at 800 nm.
Results: In the case of Nd/Yb FAp the host matrix absorption and emission was observed,
hence Nd/Yb was synthesized without citrate. On heat treatment of this for optical activation
studies, when the Yb3+ concentration was increased to 10 mol%, the YbPO4 secondary
phase was found to appear. Although, the Yb/Er FAp system resulted in large grain
growth, no such grain growth was observed in Nd/Yb FAp and the grains were within the
nano size regime even after heat treatment.
Conclusion: Both the systems showed successful energy transfer from sensitizer to activator
with a quantum yield of 74% for Yb/Er FAp and energy transfer efficiency of 71% for
Nd/Yb FAp system. Both the samples were found to be cytocompatible and has the potential
for using as probes for bioimaging applications.