In situ synthesis of biocompatible NaY 1¿x Gd x F 4 :Yb/Er nanoparticles for cell labeling and temperature sensing

Biocompatible, up-converting NaY1-xGdxF4:Yb/Er nanoparticles have been successfully obtained in situ by chitosan assisted solvothermal synthesis, and were further characterized to check their potential for optical thermometry. The temperature dependent change in the green emission intensity, originating from the thermalization between 4S3/2 and 2H11/2 levels, implied maximum relative sensitivity of 1.3 %K−1 in the physiologically interesting temperature range. Presence of chitosan ligands at the nanoparticles surface promotes their biocompatibility. The nanoparticles concentration ranging from 10 to 50 µg/mL yielded viability higher than 80 % for HS-5 fibroblast and SCC-25 oral cancer cells. Efficient visualization of αNaY0.65Gd0.15F4:Yb0.18Er0.02 nanoparticles in cytoplasmic region of cells, under excitation at 976 nm, validates their potential to be used for cell labeling and temperature sensing in tissue.

nay1-xgdxf4:yb/er; nanoparticles; upconversion luminescence; temperature sensing; cell labeling

In situ synthesis of biocompatible NaY 1¿x Gd x F 4 :Yb/Er nanoparticles for cell labeling and temperature sensing Articles