Pharmaceutical Chemistry

Lanthanide-doped Gadolinium nanoparticles have attracted considerable attention due to their promising applications in biological imaging. Sodium gadolinium fluoride (β-NaGdF₄) acts as a perfect host material for doping of luminescent lanthanide ions. Presence of seven unpaired electrons in Gd⁺³ ion, its large magnetic moment and long electronic relaxation time makes it an ideal candidate to enhance water proton relaxation rates. Therefore, Gd-based nanoparticles may also be applied as MRI contrast agents. Due to heavy nature of Gadolinium, it can strongly absorb X-ray radiations.  In this work, sodium gadolinium fluoride is doped with ytterbium and erbium to produce β-NaGdF₄:Yb/Er as core nanoparticles. They are subsequently coated with sodium gadolinium fluoride doped with neodymium (β-NaGdF₄:Nd) to produce β-NaGdF4:Yb/Er@β-NaGdF4:Nd core-shell nanoparticles. Dynamic Light Scattering (DLS), X-ray Diffraction (XRD) and Transmission electron microscopy (TEM) techniques were used for the characterization of nanoparticles. Gadolinium-based nanoparticles doped with Yb and Er or Yb and Tm have proved to be useful up-converting materials. Nanoparticles reported in this work are expected to be useful trimodal contrast agents for Photoluminescence, X-ray tomography (CT), Magnetic Resonance Imaging (MRI).