1 research outputs found
Polypeptide-Functionalized NaYF<sub>4</sub>:Yb<sup>3+</sup>,Er<sup>3+</sup> Nanoparticles: Red-Emission Biomarkers for High Quality Bioimaging Using a 915 nm Laser
We
prepared poly-l-aspartic acid (PASP) functionalized NaYF<sub>4</sub>:Yb<sup>3+</sup>,Er<sup>3+</sup> upconversion nanoparticles
(UCNP-PASP). These nanoparticles can give red upconversion emission
under excitation at 915 nm, whose wavelength of emission and excitation
is located in the optical window of biological tissue. Dynamic laser
scatting and zeta potentials of UCNP-PASP were used to study their
stabilities in different aqueous solution. To understand the mechanism
of the red emission of UCNP-PASP, photoluminescence spectra of samples
were recorded before and after modification with PASP, poly acrylic
acid (PAA), and polyÂ(ether imide) (PEI) ligands under excitation at
915 and 980 nm, respectively. The cytotoxicity of the UCNP-PASP was
also examined on a A549 cell and KB cell by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium
bromide (MTT) assay. Moreover, the PASP-functionalized UCNP was employed
as a potential biomarker for in vitro and in vivo experiments of upconversion
luminescence imaging