Functionalized YVO4:Eu3+ nanophosphors with desirable properties for biomedical applications

Highly luminescent nanophosphors (NPs) containing rare earth (RE) ions were successfully prepared by careful control of nanosynthesis. The YVO4:Eu3+ NPs formed core/shell structures with sizes from 10 nm to 25 nm. The NPs were functionalized with biocompatible groups such as OH, NH2 and SCN. A chemical coupling reaction connected the functionalized YVO4:Eu3+ NPs with Biotin via a direct reaction between the functional groups or an intermediate linker. Under UVIS excitation, YVO4:Eu3+ NPs exhibited strong red luminescence with narrow bands corresponding to the intra 4f transitions of D05-Fj7 (j = 1, 2, 3, 4) Eu3+. The peaks were found at 594 nm (D05-F17), 619 nm (D05-F27), 652 nm (D05-F37) and 702 nm (D05-F47) with the strongest emission at 619 nm. The fluorescence intensity and stability of the functionalized YVO4:Eu3+ NPs have been increased. This is a promising result in sense of using the conjugates of YVO4:Eu3+ and a bioactive molecule, Biotin for the development of a fluorescent label tool in biomedical analysis.