Facile synthesis and enhanced luminescence properties of Cu2-xS@YF3:Yb–Er core-shell nanoparticles

Abstract

Up-converting luminescent nanoparticles (UCNPs) have been arousing increasing attention in biomedical imaging because of their long-life emission and concomitant benefits (e.g., zero-autofluorescence background, low toxicity). However, the further development on the application has been limited by the low luminescence efficiency and intensity of UCNPs. Herein we report the design principle, synthesis route, and luminescence properties of core-shell structured Cu2-x[email protected]3:Yb–Er nanoparticles with strong luminescent property (red emission). The design principle leverages on the plasmon-enhanced localized electric fields effect of the interface of Cu2-xS and YF3:Yb–Er nanoparticles and photo-thermal effect of Cu2-xS. This strategy could enhanced luminescence properties of YF3:Yb–Er nanoparticles. The as-prepared Cu2-x[email protected]3:Yb–Er nanoparticles possessed stronger luminescent property (red emission) than individually dispersed YF3:Yb–Er nanoparticles. And the nanoparticles presented a dramatic red-shift that was due to the growth of YF3:Yb–Er on the Cu2-xS surface. The research supplies an insight on the development of nonmetallic plasmon-sensitized luminescent materials, and hopefully it could promote them application in the diagnosis and treatment of cancer.