Nanocrystalline infrared-to-visible up-conversion phosphors, ytterbium and erbium co-doped sodium yttrium fluoride, were synthesized. Spherical particles with narrow size distribution were prepared by a co-precipitation method in the presence of ethylenediaminetetraacetic acid (EDTA). Particles of controlled size in the range of 37 to 166 nm diameter were obtained by adjusting the molar ratio of EDTA to total lanthanides. Although the as-prepared nanoparticles emit very weak up-conversion fluorescence when excited by infrared light, the emission was enhanced by up to 40-fold after they were annealed at temperatures between 400 and 600°C. By comparison with the bulk phosphor, the luminescence efficiency of the nanoparticle was estimated to be 1%. Factors affecting the particle size and their up-conversion fluorescence intensity were investigated by various microscopic and spectroscopic techniques. Preliminary results demonstrated the nanoparticles as promising upconverting fluorescence labels in the detection of biological interactions.Phosphors are defined as solid, inorganic, crystalline materials that show luminescence upon excitation. 1 Those that emit lower energy photons when excited with higher energy photons are down-conversion phosphors. For example, ZnS:Mn and Y 2 O 3 :Eu, are well-known down-conversion phosphors. [2][3][4][5] On the other hand, phosphors that emit higher energy photons after absorbing lower energy excitation photons are up-conversion phosphors. 6 At least two lower energy photons are required to generate one higher energy photon. There is growing interest in studying up-conversion phosphors, because they are one of the most promising materials for the production of solid-state lasers, especially blue-light-emitting lasers. Up to now, red, green, and blue laser sources pumped by infrared light at room temperature have been reported. 7 Meanwhile, the use of up-conversion phosphors as fluorescent labels for the sensitive detection of biomolecules has attracted even more interest recently. [8][9][10][11] Traditionally, most of the biological luminescent labels are organic dyes, such as rhodamine, fluorescein isothiocyanates (FITC), and cyanine dyes (Cy3, Cy5, and Cy7). More recently, metal and semiconductor nanocrystals have been employed as labels in biological detections. [12][13] The perceived advantages of the fluorescent nanocrystals are their high quantum yield, tuneable emission wavelength, and high stability against photobleaching. In comparison with downconversion fluorescent materials, up-conversion fluorescent labels show very low background light due to their unique fluorescence properties. Excitation is performed using an infrared laser, which is compact, power-rich, and also inexpensive. 14 As with the down-conversion organic dyes, the up-conversion phosphors are usually stable, nonfading,

Photothermal therapy (PTT) is attracting increasing interest and becoming more widely used for skin cancer therapy in the clinic, as a result of its noninvasiveness and low systemic adverse effects. However, there is an urgent need to develop biocompatible PTT agents, which enable accurate imaging, monitoring, and diagnosis. Herein, a biocompatible Gd-integrated CuS nanotheranostic agent (Gd:CuS@BSA) was synthesized via a facile and environmentally friendly biomimetic strategy, using bovine serum albumin (BSA) as a biotemplate at physiological temperature. The as-prepared Gd:CuS@BSA nanoparticles (NPs) with ultrasmall sizes (ca. 9 nm) exhibited high photothermal conversion efficiency and good photostability under near-infrared (NIR) laser irradiation. With doped Gd species and strong tunable NIR absorbance, Gd:CuS@BSA NPs demonstrate prominent tumor-contrasted imaging performance both on the photoacoustic and magnetic resonance imaging modalities. The subsequent Gd:CuS@BSA-mediated PTT result shows high therapy efficacy as a result of their potent NIR absorption and high photothermal conversion efficiency. The immune response triggered by Gd:CuS@BSA-mediated PTT is preliminarily explored. In addition, toxicity studies in vitro and in vivo verify that Gd:CuS@BSA NPs qualify as biocompatible agents. A biodistribution study demonstrated that the NPs can undergo hepatic clearance from the body. This study highlights the practicality and versatility of albumin-mediated biomimetic mineralization of a nanotheranostic agent and also suggests that bioinspired Gd:CuS@BSA NPs possess promising imaging guidance and effective tumor ablation properties, with high spatial resolution and deep tissue penetration.

Currently, protein/peptide-based biomimetic mineralization has been demonstrated to be an efficient and promising strategy for synthesis of inorganic/metal nanoparticles (NPs) for bioapplications.

This review focuses on alkyl length effects on solid-state fluorescence and mechanochromic behaviors, and the purpose is to arouse one's further attention to the alkyl-length effect in the design, synthesis and structure–property investigation of organic optoelectronic materials.

Structurally controlled nanoparticles, such as core-shell nanocomposite particles by combining two or more compositions, possess enhanced or new functionalities that benefited from the synergistic coupling of the two components. Here we report new nanocomposite particles with self-assembled porphyrin arrays as the core surrounded by amorphous silica as the shell. The synthesis of such nanocomposite nanoparticles was conducted through a combined surfactant micelle confined self-assembly and silicate sol-gel process using optically active porphyrin as a functional building block. Depending on kinetic conditions, these particles exhibit structure and function at multiple length scales and locations. At the molecular scale, the porphyrins as the building blocks provide well-defined macromolecular structures for noncovalent self-assembly and unique chemistry for high-yield generation of singlet oxygen for photodynamic therapy (PDT). On the nanoscale, controlled noncovalent interactions of the porphyrin building block result in an extensive self-assembled porphyrin network that enables efficient energy transfer and impressive fluorescence for cell labeling, evidenced by absorption and photoluminescence spectra. Finally, the thin silicate shell on the nanoparticle surface allows easy functionalization, and the resultant targeting porphyrin-silica nanocomposites can selectively destroy tumor cells upon receiving light irradiation.

A new pure fluorescent blue HLCT-emitter was designed and synthesized. Highly efficient non-doped blue OLEDs with low efficiency roll-off were achieved.

Patients are increasingly being diagnosed with neuropathic diseases, but are rarely cured because of the loss of neurons in damaged tissues. This situation creates an urgent clinical need to develop alternative treatment strategies for effective repair and regeneration of injured or diseased tissues. Neural stem cells (NSCs), highly pluripotent cells with the ability of self-renewal and potential for multidirectional differentiation, provide a promising solution to meet this demand. However, some serious challenges remaining to be addressed are the regulation of implanted NSCs, tracking their fate, monitoring their interaction with and responsiveness to the tissue environment, and evaluating their treatment efficacy. Nanomaterials have been envisioned as innovative components to further empower the field of NSC-based regenerative medicine, because their unique physicochemical characteristics provide unparalleled solutions to the imaging and treatment of diseases. By building on the advantages of nanomaterials, tremendous efforts have been devoted to facilitate research into the clinical translation of NSC-based therapy. Here, recent work on emerging nanomaterials is highlighted and their performance in the imaging and treatment of neurological diseases is evaluated, comparing the strengths and weaknesses of various imaging modalities currently used. The underlying mechanisms of therapeutic efficacy are discussed, and future research directions are suggested.

2,6,9,10-tetra(p-dibutylaminostyryl)anthracene exhibited semi-disjointed frontier molecular orbital and multifunctional optical properties, including aggregation-enhanced emission, enhanced two-photon absorption activity, fluorescence response selectively to TM ions, and piezochromic luminescence. These are rarely found in cruciform configuration dyes.