ABSTRACT
Invited for this month's cover are the collaborating groups of Dr. Loïcâ J. Charbonnière at CNRS/Université de Strasbourg, France and Dr. Ka-Leung Wong at Hong Kong Baptist University, Hong Kong. The cover picture shows terbium-doped LaF3 nanoparticles that are surface functionalized by photon-harvesting antenna ligands. Surface capping with antenna ligands leads to ultrabright nanoparticles, with the typical green luminescence signature of the Tb atoms and very long excited-state lifetimes. These lanthanide dots can be incorporated into living cells at nanomolar concentrations for luminescence microscopy imaging. Read the full text of the article at 10.1002/cplu.201600007.
ABSTRACT
Tb-doped La0.9 Tb0.1 F3 nanoparticles were prepared by a simple and reproducible microwave-assisted synthetic protocol in water. The nanoparticles were characterized by XRD, TEM, dynamic light scattering and inductively coupled plasma atomic emission spectroscopy elemental analysis. Eleven ligands with varying coordination and photosensitizing abilities were designed to bind at the surface of the Tb-doped nanoparticles. The photosensitizing behavior was monitored by electronic absorption spectroscopy and steady-state and time-resolved emission spectroscopy. The two most effective photosensitizing ligands were used to isolate and purify the capped nanoparticles. The composition and spectroscopic properties of these nanoparticles were measured, which revealed either 2660 and 5240â ligands per nanoparticle, molar absorptivities of 7.6×106 and 1.6×107 m-1 cm-1 and luminescence quantum yields of 0.29 and 0.13 in water, respectively. These data correspond to exceptional brightness values of 2.2×106 and 2.1×106 m-1 cm-1 , respectively. The as-prepared nanoparticles were imaged in HeLa cells by fluorescence microscopy, which showed their specific localization in lysosomes.
