Barium yttrium fluoride based upconversion nanoparticles as dual mode image contrast agents

Abstract Dual labeled contrast agents could provide better complementary information for bioimaging than available solely from a single modality. In this paper we investigate the suitability of Yb3+ and Er3+-doped BaYF5 upconversion nanoparticles (UCNPs) as both optical X-ray micro computed tomography (?CT) agents. Stable, aqueous UCNP dispersions were synthesised using hydrothermal method with addition polyethyleneimine (PEI). UCNPs crystal had truncated cuboidal and/or octahedral morphology, average particle size 47 ±9 nm transmission electron microscopy which was further used to characterize structure composition in detail. A zeta potential value +51 mV measured nanoparticle is beneficial cell permeability. The outer hydrated PEI layer also advantageous attachment proteins targeted delivery biological systems. prepared proven be non-toxic endothelial cells up concentration 3.5 mg/mL, when assessed an MTT assay. particles showed intense green photoluminescence excited at wavelength 976 nm diode laser. Quantitative ?CT imaging confirmed these confirming their dual modality bioimaging.