Synthesis and functionalization of biocompatible Tb:CePO4 nanophosphors with spindle-like shape

Abstract

Abstract:Monoclinic Tb:CePO4 nanophosphors with a spindle-like morphology and tailored size have been prepared though a very simple procedure, which consists of aging, at low temperature (120ºC), ethylene glycol solutions containing only cerium and terbium acetylacetonates and phosphoric acid, not requiring the addition of surfactants or capping agents. The influence of the heating mode (conventional convection oven or microwave oven) and the Tb doping level on the luminescent, structural and morphological features of the precipitated nanoparticles have been also analyzed. This study showed that microwave-assisted heating resulted in an important beneficial effect on the luminescent properties of these nanophosphors. Finally, a procedure for the functionalization of the Tb:CePO4 nanoparticles with aspartic-dextran is also reported. The functionalized nanospindles presented negligible toxicity for Verocells and a high colloidal stability when dispersed in water (pH=6.7), which along with theirs excellent luminescent properties, make them suitable for biomedical applications. The functionalized nanospindles presented negligible toxicity for Verocells and a high colloidal stability when dispersed in water (pH=6.7), which along with theirs excellent luminescent properties, make them suitable for biomedical applications. Powered by Editorial Manager® and Preprint Manager® from Aries Systems Corporation

New Single-Phase, White-Light-Emitting Phosphors Based on δ-Gd2Si2O7 for Solid-State Lighting

“…Therefore, both lanthanides can simultaneously be excited through the Gd-Ln energy-transfer band. (ii) Likewise, Tb 3+ in low concentrations is able to emit not only green but also blue light after excitation with UV radiation, − although this emission is not a common feature of all matrices. , A single-phase white-light-emitting δ-Gd 2 Si 2 O 7 phosphor could therefore be synthesized if the latter emission is confirmed for Tb-doped δ-Gd 2 Si 2 O 7 by combining the red emission from Eu 3+ with the green and blue emissions from Tb 3+ by using the appropriate doping concentrations of both ions.…”

Transcription of Nanofibrous Cerium Phosphate Using a pH-Sensitive Lipodipeptide Hydrogel Template

“…As in the case of as-prepared samples, templated CePO 4 showed a considerably higher emission with respect to reference sample. It must be also highlighted that, although monoclinic CePO 4 (monazite) is supposed to have improved photoluminescence emission than hexagonal CePO 4 , due to the luminescence quenching effect induced by the water molecules still retained in hexagonal CePO 4 [22,104], in our case the emission of both monazite-based CePO 4 samples (900 °C-annealed in air conditions) was considerably lower than the emission shown by as-prepared (hexagonal) CePO 4 . Again, this fact could be explained by the presence of uniform nanofibrous morphologies in as-prepared CePO 4 materials, in contrast with the rounded nano-grained bulk aggregates with non-uniform morphologies present in both monazite-based CePO 4 samples annealed at 900 °C under air conditions.…”

“…Rare-earth phosphates (from now on, RPO 4 ) are being prolifically investigated during the last decades given the wide variety of interesting properties they may exhibit, such as optical, electronical (or optoelectronical), ion-exchange, catalytic, heat-resistance, and biocompatibility, among others. These advanced properties have enabled the application of RPO 4 , especially CePO 4 and related solid solutions (with Tb, Gd, or other lantanides) and composite systems (Au/CePO 4 ,...) in a plethora of technological applications, such as optoelectronic devices (luminescent materials, phosphors, displays, green light-emitting diodes or switches, solid-state lasers, redox sensors, non-linear optical devices,...) [1,2,3,4,5,6,7,8,9,10,11,12,13], fluorescent probes for chemical sensing [14,15,16] and detection or removal of heavy metals (e.g., Pb 2+ , Co 2+ ,...) [17,18], bio-sensing, bio-imaging and cell-labeling applications [19,20,21,22,23], ceramic materials (with high thermal and mechanical properties) [24], dielectrics [25], catalysts [26,27,28,29,30], ion-exchange or ion-conducting materials (proton-conducting membranes) for solid-oxide fuel cells (SOFCs) [25,31] and solar-cells, ceramic pigments [32,33,34], UV filters for sunscreens [35], and so on.…”

“…In the case of lanthanide phosphate materials, e.g., CePO 4 and related solid solutions, composite systems and core–shell heterostructures, the preparation of highly-anisotropic 1D nanostructures with different morphologies (such as nanowires, nanorods, nanobelts, nanotubes, nanobars, nanocables, spindle-like, etc.) has led to highly-efficient and even better-performant photoluminescent, optoelectronic or electrochemical devices, sensors and biomaterials [1,2,3,4,5,6,9,11,15,16,20,21,22,38,39,40,41,42,43,44,45,46,47,48,49,50,51].…”

“…Recent investigations have also evidenced that the properties of CePO 4 nanoarchitectures depend strongly on its dimensionality, morphology, size, shape and size uniformity and crystallinity (structure- and morphology-properties relationships), and these aspects are very sensitive to the employed synthesis methodology [1,3,4,5,6,7,8,12,13,41,48,49,50,51,52,53,54,55,56]. In this respect, although, 1D RPO 4 nanomaterials like CePO 4 may be prepared by relatively facile or simple solution methods [4,52,54], the controlled synthesis of these nanomaterials often requires the employment of non-conventional routes such as sol-gel [24,34], hydrothermal [3,5,7,38,39,41,43,48,49,57,58,59], microemulsion [45,60], sonochemical [18,51,61,62], or microwaves-assisted methods (combined or not with hydrothermal or solvothermal treatments) [9,22,42,56]. In these methods, the addition of chelating or complexing additives and surfactants is often necessary [1,5,7,30,45,55,63], and a rigorous and judicious control of synthesis conditions is generally needed to obtain the desired morphology, including preparation variables such as the chosen Ce and phosphate sources, the P/Ce ratio, reaction temperature and time, pH and ageing conditions, the order and speed of precursors addition (rapid vs. dropwise or continuous-flow) [4,…”