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.