Ultrabright Lanthanide Nanoparticles

Abstract

Tb‐doped La0.9Tb0.1F3 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 5240 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.

Ultrafast Synthesis and Coating of High-Quality β-NaYF4:Yb3+,Ln3+ Short Nanorods

“…[13][14] Indeed, this route has already been employed to prepare different fluoride materials. [15][16][17] However, the accurate attribution of the crystalline phase is difficult in small nanocrystals and even sometimes avoided by the authors, since it is a crucial issue in highly sensitive luminescent systems. Reports concerning UC NaYF4 encompass either small nanoparticles (< 8 nm) of the 10-times less efficient α-phase [18][19][20] and α/β mixtures, 21 or pure β-phase prisms 20,22 and long wires 23 of micrometric size.…”

Chiroptical Spectroscopic Studies on Lanthanide Complexes with Valinamide Derivatives in Solution

“…[5] It is also known that the nature of electronic transitions of rare earth ions, such as europium (Eu), terbium (Tb), may be induced and their optical properties affected by coordination systems that can enhance the CPL. [6][7][8][9][10][11][12][13] It is useful to use chiral biological species to sensitize the chiroptical spectra of molecules. Figure 1 shows two lanthanide complexes having tetradentate and hexadentate ligands, abbreviated as EuL val and EuL me , respectively, that we used herein.…”

Spectroscopic Properties of a Family of Mono‐ to Trinuclear Lanthanide Complexes

“…It is well established that the accumulation of fluorescent compounds may lead to a loss of some of the fluorescence properties by self‐quenching through homo‐FRET (Förster resonance energy transfer) or formation of excimers or exciplexes, as stacking interactions become important for polyaromatic compounds. In the case of Ln‐doped luminescent solids, the antenna effect can also be beneficial to increase the overall brightness,, but the phenomenon of self‐quenching was also observed when the concentration of the active emitting Ln cations becomes too high . The phenomenon was first ascribed to the presence of quenching impurities, which, after migration of the excitation energy through the solid, lead to non‐radiative deactivation.…”