Research progress in upconversion nanophosphors for biological imaging

The upconversion nanophosphors are a kind of fluorescence materials with near infrared excitation and short wavelength emission. The upconversion nanophosphors can compensate for the deficiencies of the traditional fluorescent labeling materials because of the stability, non-photobleaching, weak photodamage of biological samples, and high fluorescence signal to noise ratio of biological samples. This review focuses on the upconversion nanophosphors in bioimaging applications.