Yb³⁺,Er³⁺,Eu³⁺-codoped YVO₄ material for bioimaging with dual mode excitation

We propose an efficient bioimaging strategy using Yb³⁺,Er³⁺,Eu³⁺-triplet doped YVO₄ nanoparticles which were synthesized with polymer as a template. The obtained particles possess nanoscale, uniform, and flexible excitation. The effect of Eu³⁺ ions on the luminescence properties of YVO₄:Yb³⁺,Er³⁺,Eu³⁺ was investigated. The upconversion mechanism of the prepared material was also discussed. The structure and optical properties of the prepared material were characterized by using X-ray diffraction (XRD), Fourier-transform IR spectroscopy (FTIR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) upconversion and photoluminescence spectra. The Commission International de I'Eclairage (CIE) chromaticity coordinates was investigated to confirm the performance of color luminescent emission. The prepared YVO₄:Yb³⁺,Er³⁺,Eu³⁺ nanoparticles could be easily dispersed in water by surface modification with cysteine (Cys) and glutathione (GSH). The aqueous dispersion of the modified YVO₄:Yb³⁺,Er³⁺,Eu³⁺ exhibits bright upconversion and downconversion luminescence and has been applied for bioimaging of HeLa cells. Our developed material with dual excitation offers a promising advance in bioimaging.