Dual-functional [beta]-NaYF sub(4): Yb super(3+), Er super(3+) nanoparticles for bioimaging and temperature sensing

Hexagonal-phase NaYF sub(4): Yb super(3+), Er super(3+) nanoparticles (NPs) have been widely used as the most efficient NIR-to-visible upconversion (UC) luminescent and probe in bioscience. Here, we exploited not only the function of dual-mode emission of [beta]-NaYF sub(4): Yb super(3+), Er super(3+) NPs in the near infrared (NIR) and visible regions with single wavelength excitation at 980 nm, but also the function of physiological temperature sensing with the luminescence of Er super(3+) in the visible region. The structural and optical characteristics of [beta]-NaYF sub(4): Yb super(3+), Er super(3+) NPs were obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM),and fluorescence spectral measurements, respectively; the mechanism for the energy transfer has been suggested with emphasis on the optimized Er/Yb concentration for most efficient UC. Due to the UC and down-shifting NIR properties, we achieved the dual-functional nanoparticles with potential application in physiological range temperature sensing and bioimaging simultaneously.