Mechanistic investigation of photon upconversion in Nd(3+)-sensitized core-shell nanoparticles.
A new type of core-shell upconversion nanoparticles which can be effectively excited at 795 nm has been designed and synthesized through spatially confined doping of neodymium (Nd(3+)) ions. The use of Nd(3+) ions as sensitizers facilitates the energy transfer and photon upconversion of a series of lanthanide activators (Er(3+), Tm(3+), and Ho(3+)) at a biocompatible excitation wavelength (795 nm) and also significantly minimizes the overheating problem associated with conventional 980 nm excitation. Importantly, the core-shell design enabled high-concentration doping of Nd(3+) (~0 mol %) in the shell layer and thus markedly enhanced the upconversion emission from the activators, providing highly attractive luminescent biomarkers for bioimaging without autofluorescence and concern of overheating.
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Xiaoji
X
Xie
Nengyue
N
Gao
Renren
R
Deng
Qiang
Q
Sun
Qing-Hua
QH
Xu
Xiaogang
X
Liu