Paper Title
A Study on Facile Synthesis of Yb3+, Er3+, Eu3+-Codoped Yvo4 Nanomaterial And its Application

Abstract
In this work, a simple method for the synthesis of Yb3+, Er3+, Eu3+ coped- YVO4upconversionnanoparticles using polymer as a template is proposed. The obtained particles possess nanoscaleuniform, and flexible excitation. The structure and optical properties of prepared material have been carefully studied. Effect of Eu3+ ions on the luminescence properties of YVO4:Yb3+,Er3+,Eu3+ was performed. The upconversion mechanism of prepared material was discussed.The results were characterized by 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 due to surface modification with cysteine (Cys) and glutathione (GSH). Importantly, the aqueous dispersion of modified YVO4:Yb3+,Er3+,Eu3+ exhibited bright upconversion and downconversion luminescence and it could be used for imaging HeLa cells. Keywords: Nanomaterials, Upconversion, Bioimaging�.