Single upconversion nanoparticle imaging at sub-10 W cm^-2 irradiance.

ABSTRACT: Lanthanide-doped upconversion nanoparticles (UCNPs) are promising single-molecule probes given their non-blinking, photobleach-resistant luminescence upon infrared excitation. However, the weak luminescence of sub-50 nm UCNPs limits their single-particle detection to above 10 kWcm^-2 that is impractical for live cell imaging. Here, we systematically characterize single-particle luminescence for UCNPs with various formulations over a 10⁶ variation in incident power, down to 8 Wcm^-2. A core-shell-shell (CSS) structure (NaYF₄@NaYb_1-xF₄:Er_x@NaYF₄) is shown to be significantly brighter than the commonly used NaY_0.78F₄:Yb_0.2Er_0.02. At 8 Wcm^-2, the 8% Er

SUBMITTER: Liu Q 

PROVIDER: S-EPMC6599589 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature