Controlled Synthesis and Water Dispersibility of Hexagonal Phase NaGdF4:Ho3+/Yb3+ Nanoparticles

Naccache, Rafik; Vetrone, Fiorenzo; Mahalingam, Venkataramanan; Cuccia, Louis A.; Capobianco, John A.

doi:10.1021/cm803151y

Cited by 371 publications

(270 citation statements)

References 30 publications

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“…1 F and I and 2G). The intensity ratio of green to red emission from the NRs increases as the Ho 3þ concentration increases from 1% to 2%, owing to the enhanced energy transfer from the Yb 3þ sensitizers to adjacent Ho 3þ ions (37). Furthermore, trivalent Ce 3þ ions are introduced to modulate the upconversion profiles of the NaYF 4 : Yb/Ho (20∕2 mol%) UCNPs.…”

Section: Resultsmentioning

confidence: 99%

Morphologically controlled synthesis of colloidal upconversion nanophosphors and their shape-directed self-assembly

Collins

Kang

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

424

379

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We report a one-pot chemical approach for the synthesis of highly monodisperse colloidal nanophosphors displaying bright upconversion luminescence under 980 nm excitation. This general method optimizes the synthesis with initial heating rates up to 100°C∕ minute generating a rich family of nanoscale building blocks with distinct morphologies (spheres, rods, hexagonal prisms, and plates) and upconversion emission tunable through the choice of rare earth dopants. Furthermore, we employ an interfacial assembly strategy to organize these nanocrystals (NCs) into superlattices over multiple length scales facilitating the NC characterization and enabling systematic studies of shape-directed assembly. The global and local ordering of these superstructures is programmed by the precise engineering of individual NC's size and shape. This dramatically improved nanophosphor synthesis together with insights from shape-directed assembly will advance the investigation of an array of emerging biological and energy-related nanophosphor applications.doped nanocrystals | superlattice | lanthanides | luminescence R ecent advances in synthesis and controlled assembly of monodisperse colloidal nanocrystals (NCs) into superlattice structures have enabled their applications in optics (1), electronics (2), magnetic storage (3), etc. Single-and multicomponent superlattices composed of spherical NCs are increasingly studied and a rich family of structures is now accessible (4, 5), where the electronic and magnetic interactions between the constituents gives rise to new cooperative properties (6, 7). New synthetic approaches are yielding nonspherical NCs with physical properties unobtainable by simply tuning the size of the spheres (8-11), providing an even broader array of nanoscale building blocks. The size and shape dependence of NC's biological activity (12, 13) and toxicity (14) is also of intense interest. However, the challenge of precisely controlling particle shape while maintaining uniformity in size and surface functionality has limited studies of NC environmental health and safety just as it has hindered efforts to organize anisotropic building blocks and to establish methods to capture their unique properties in NC superlattice thin films.Lanthanide-doped nanophosphors are an emerging class of optical materials (15). These NCs often possess "peculiar" optical properties [e.g., quantum cutting (16) and photon upconversion (17)], allowing the management of photons that could benefit a variety of areas including biomedical imaging (18, 19) and therapy (20), photovoltaics (16, 21), solid state lighting (22), and display technologies (23). Colloidal upconversion nanophosphors (UCNPs) are capable of converting long-wavelength near-infrared excitation into short-wavelength visible emission through the long-lived, metastable excited states of the lanthanide dopants (24). In contrast to the Stokes-shifted emissions from semiconductor NCs or organic fluorophores and the multiphoton process employing fluorescent dyes, UCNPs offer several ...

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Section: Resultsmentioning

confidence: 99%

Morphologically controlled synthesis of colloidal upconversion nanophosphors and their shape-directed self-assembly

Collins

Kang

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

424

379

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“…Frequently used additives for the functionalization of RE-based NPs are sodium citrate, PAA, PEG and derivate, poly(allylamine hydrochloride) (PAH), poly(sodium 4-styrenesulfonate) (PSS), 1,2-distearoyl-snglycero-3-phospho-ethanolamine-N-[methoxy(poly-ethyleneglycol)-2000] (ammonium salt) and the amphiphilic polymer poly(isobutylene-alt-maleic anhydride) modified with dodecylamine (PMA) and its derivate [74,141]. A functionalization step is mandatory for hydrophobic NPs synthesized in organic media [83].…”

Section: Functionalization Strategiesmentioning

confidence: 99%

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

et al. 2017

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Abstract:Rare earth based nanostructures constitute a type of functional materials widely used and studied in the recent literature. The purpose of this review is to provide a general and comprehensive overview of the current state of the art, with special focus on the commonly employed synthesis methods and functionalization strategies of rare earth based nanoparticles and on their different bioimaging and biosensing applications. The luminescent (including downconversion, upconversion and permanent luminescence) and magnetic properties of rare earth based nanoparticles, as well as their ability to absorb X-rays, will also be explained and connected with their luminescent, magnetic resonance and X-ray computed tomography bioimaging applications, respectively. This review is not only restricted to nanoparticles, and recent advances reported for in other nanostructures containing rare earths, such as metal organic frameworks and lanthanide complexes conjugated with biological structures, will also be commented on.

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“…285,468 With the advent of nanotechnology, there has also been a continuous increase in organic and inorganic core-shell nanoparticle discoveries with exceptional properties. 8 This gave rise to the discovery of several types of core-shell microstructures, such as spherical 256,284,285,468 , hexagonal 469,470 , multiple cores within a single shell 471,472 , onion-like 473,474 , movable core within shell 475,476 , and 2-D structures such as rods [477][478][479] , among others. A general notation is described here in an attempt to standardize the nomenclature used to define core-shell microstructures.…”

Section: Appendix I: Nomenclature For Core-shell Microstructuresmentioning

confidence: 99%

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

Acosta

2016

Springer Theses

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Controlled Synthesis and Water Dispersibility of Hexagonal Phase NaGdF₄:Ho³⁺/Yb³⁺ Nanoparticles

Cited by 371 publications

References 30 publications

Morphologically controlled synthesis of colloidal upconversion nanophosphors and their shape-directed self-assembly

Morphologically controlled synthesis of colloidal upconversion nanophosphors and their shape-directed self-assembly

Rare earth based nanostructured materials: synthesis, functionalization, properties and bioimaging and biosensing applications

Strain Mechanisms in Lead-Free Ferroelectrics for Actuators

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