(alpha-NaYbF4:Tm3+)/CaF2 Core/Shell Nanoparticles with Efficient Near-Infrared to Near-Infrared Upconversion for High-Contrast Deep Tissue Bioimaging
2012 (English)In: ACS Nano, ISSN 1936-0851, Vol. 6, no 9, 8280-8287 p.Article in journal (Refereed) Published
We describe the development of novel and biocompatible core/shell (alpha-NaYbF4:Tm3+)/CaF2 nanoparticles that exhibit highly efficient NIRin-NIROut upconversion (UC) for high contrast and deep bioimaging. When excited at similar to 980 nm, these nanoparticles emit photoluminescence (PL) peaked at similar to 800 nm. The quantum yield of this UC PL under low power density excitation (similar to 0.3 W/cm(2)) is 0.6 +/- 0.1%. This high UC PL efficiency is realized by suppressing surface quenching effects via heteroepitaxial growth of a biocompatible CaF2 shell, which results in a 35-fold increase in the intensity of UC PL from the core. Small-animal whole-body UC PL imaging with exceptional contrast (signal-to-background ratio of 310) is shown using BALB/c mice intravenously injected with aqueously dispersed nanoparticles (700 pmol/kg). High-contrast UC PL imaging of deep tissues is also demonstrated, using a nanoparticle-loaded synthetic fibrous mesh wrapped around rat femoral bone and a cuvette with nanoparticle aqueous dispersion covered with a 3.2 cm thick animal tissue (pork).
Place, publisher, year, edition, pages
2012. Vol. 6, no 9, 8280-8287 p.
near-infrared, photoluminescence bioimaging, upconversion nanocrystals, lanthanide, core/shell
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-104381DOI: 10.1021/nn302972rISI: 000309040600081ScopusID: 2-s2.0-84866639563OAI: oai:DiVA.org:kth-104381DiVA: diva2:564837
FunderSwedish e‐Science Research Center
QC 201211052012-11-052012-11-012013-04-08Bibliographically approved