Sol–Gel-Derived Biodegradable Er-Doped ZnO/Polyethylene Glycol Nanoparticles for Cell Imaging

Abstract

Zinc oxide nanoparticles (ZnO NPs) as promising and nontoxic fluorescent labels are currently developed for cell imaging owing to their excellent biocompatibility. However, the low intensity of the emission band and stability of ZnO NPs have restricted their further applications. In this work, 5 mol % rare-earth metal erbium (Er)-doped ZnO nanoparticles with poly(ethylene glycol) (PEG) surface modification (Er-doped ZnO/PEG NPs) are fabricated by the sol–gel method. Their fluorescence characteristics and biodegradation behavior are investigated. The results indicate that the visible photoluminescence of Er-doped ZnO/PEG NPs has been dramatically enhanced by 631.6% compared with that of bare ZnO NPs. After being stored for one month, particle size variation is less than 1 nm, and fluorescence performance can be well retained. Furthermore, the degradation and cytotoxicity results confirm the degradable and biocompatible characteristics of Er-doped ZnO/PEG NPs, thus extending their potential applications for cell imaging.