Biosynthesis of silver fine particles and particles decorated with nanoparticles using the extract of Illicium verum (star anise) seeds

Given the upsurge of new technologies based on nanomaterials, the development of sustainable methods to obtain functional nanostructures has become an imperative task. In this matter, several recent researches have shown that the biodegradable natural antioxidants of several plant extracts can be used simultaneously as reducing and stabilizing agents in the wet chemical synthesis of…

Up-conversion in Er3+/Yb3+ co-doped LaPO4 submicron-sized spheres

Er3+/Yb3+ co-doped materials have been extensively used for imaging in biomedical applications using either visible up-converted (UC) or near-infrared (NIR) emissions. The UC spectrum is composed mainly by two Erbium emissions in the green (2H11/2:4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) spectral range, while the NIR spectrum includes Er3+ (λ ∼ 1.5 μm, 4I13/2 → 4I15/2) and Er3+/Yb3+ (λ ∼ 980 nm, 2F5/2 → 2F7/2(Yb3+):4I11/2 → 4I15/2 (Er3+)) transitions; which relative intensities are dependent on several…

Quick synthesis, functionalization and properties of uniform, luminescent LuPO4-based nanoparticles

The aim of this study was to find a surfactant-free method for the synthesis of uniform Eu:LuPO4nanophosphors which are able to form stable colloidal suspensions in aqueous media. Uniform, ovoid Eu-doped LuPO4 fluorescent nanoparticles were obtained after aging for 30 minutes at 180 °C a butylene glycol solution containing, exclusively, lutetium acetate, europium acetate and H3PO4.…

One-Step Synthesis and Polyacrylic Acid Functionalization of Multifunctional Europium-Doped NaGdF4 Nanoparticles with Selected Size for Optical and MRI Imaging

Multifunctional Eu:NaGdF4 nanospheres functionalized with polyacrylic acid (PAA) polymer have been prepared for the first time by a simple one-pot method that consists of a homogeneous precipitation reaction at 120 °C. The size of the nanospheres, which were polycrystalline and crystallized into a hexagonal structure, could be altered in the 60–95 nm range by adjusting the…

Síntesis y propiedades de nanopartículas luminiscentes para aplicaciones biomédicas

Las nanopartículas luminiscentes resultan de interés en Nanobiomedicina debido a sus diferentes aplicaciones, que incluyen sensores ópticos para la imagen de tejidos o estructuras intracelulares y para la detección y cuantificación de moléculas de interés biológico. En este proyecto se desarrollan nuevos métodos de síntesis de nanoestructuras uniformes de diferentes materiales inorgánicos (vanadatos, fluoruros, fosfatos…

Morphological and structural behavior of TiO2 nanoparticles in the presence of WO3: crystallization of the oxide composite system

Composite TiO2-WO3 oxide materials were prepared by a single pot microemulsion method and studied during calcination treatments under dry air in order to analyze the influence of tungsten on the behavior of the dominant titania component. To this end, the surface and bulk morphological and structural evolution of the solid precursors was studied using X-ray…

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

Two new white-light (WL)-emitting phosphors (δ-Gd2Si2O7:Dy and δ-Gd2Si2O7:Eu,Tb) have been synthesized by the sol–gel method. The Gd-Ln3+ (Ln3+= Dy3+, Tb3+, Eu3+) energy-transfer band has been used to excite both phosphors, which provides an enhancement of the Ln3+ emissions. First, WL was generated from δ-Gd2Si2O7:xDy thanks to the particular ratio of the blue and yellow emissions…

Bifunctional, Monodisperse BiPO4-Based Nanostars: Photocatalytic Activity and Luminescent Applications

Monodisperse, monoclinic BiPO4 nanostars have been synthesized by a homogeneous precipitation reaction at 120 °C through controlled release of Bi3+ cations from a Bi–citrate chelate, in a mixture of glycerol and ethylene glycol, using H3PO4 as the phosphate source. The set of experimental conditions necessary to obtain uniform nanoparticles is very restrictive, as the change…