Lanthanide-based luminescent hybrid materials.

Uniform, spherical-shaped TiO2:Eu nanoparticles with different doping concentrations have been synthesized through controlled hydrolysis of titanium tetrabutoxide under appropriate pH and temperature in the presence of EuCl3·6H2O. Through air annealing at 500°C for 2 h, the amorphous, as-grown nanoparticles could be converted to a pure anatase phase. The morphology, structural, and optical properties of the annealed nanostructures were studied using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy [EDS], and UV-Visible diffuse reflectance spectroscopy techniques. Optoelectronic behaviors of the nanostructures were studied using micro-Raman and photoluminescence [PL] spectroscopies at room temperature. EDS results confirmed a systematic increase of Eu content in the as-prepared samples with the increase of nominal europium content in the reaction solution. With the increasing dopant concentration, crystallinity and crystallite size of the titania particles decreased gradually. Incorporation of europium in the titania particles induced a structural deformation and a blueshift of their absorption edge. While the room-temperature PL emission of the as-grown samples is dominated by the 5D0 - 7Fj transition of Eu+3 ions, the emission intensity reduced drastically after thermal annealing due to outwards segregation of dopant ions.

/pdf/effects-of-crystallization-and-dopant-concentration-on-the-1axbmxo1at.pdf

Effects of crystallization and dopant concentration on the emission behavior of TiO2:Eu nanophosphors

Sasidharan Swarnalatha Lucky,†,§ Khee Chee Soo,‡ and Yong Zhang*,†,§,∥ †NUS Graduate School for Integrative Sciences & Engineering (NGS), National University of Singapore, Singapore, Singapore 117456 ‡Division of Medical Sciences, National Cancer Centre Singapore, Singapore, Singapore 169610 Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore 117576 College of Chemistry and Life Sciences, Zhejiang Normal University, Zhejiang, P. R. China 321004

Nanoparticles in photodynamic therapy.

Yuming Yang,†,§ Qiang Zhao,‡,§ Wei Feng,† and Fuyou Li*,† †Department of Chemistry and State Key Laboratory of Molecular Engineering of Polymers and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433, P. R. China ‡Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, Nanjing 210046, P. R. China.

Luminescent chemodosimeters for bioimaging.

Applications in Theranostics Guanying Chen,*,†,‡ Hailong Qiu,†,‡ Paras N. Prasad,*,‡,§ and Xiaoyuan Chen* †School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China ‡Department of Chemistry and the Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, State University of New York, Buffalo, New York 14260, United States Department of Chemistry, Korea University, Seoul 136-701, Korea Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892-2281, United States

Upconversion Nanoparticles: Design, Nanochemistry, and Applications in Theranostics

The invention relates to an open type low-temperature high-resolution ratio laser spectrum test system which mainly consists of a pump light source module, a low-temperature optical thermostat module, a high-resolution mono-chrometer module, a fluorescent life span test module, a weak signal detecting module, and the like. The open type low-temperature high-resolution ratio laser spectrum test system is characterized in that the system uses an open and modularized design idea; compared with the traditional spectrum test system, the system has the following advantages: firstly, each functional module is flexibly combined with each other through optical elements such as a reflector and a lens, and the system is in an open type; therefore, the function expandability is high, and the new functional module can be added to the system conveniently; secondly, the system has various types of test functions; besides conventional down-conversion fluorescence spectrum, exciting spectrum and micro-millisecond fluorescence life span, the system further can test up-conversion fluorescence spectrum, up-conversion fluorescence life span, and pico-second short life span of the sample at low temperature; and the maximum value of the spectrum resolution rate can reach 0.006 nm.

Open type low-temperature high-resolution ratio laser spectrum test system

The development of aggregation-induced emission luminogens (AIEgens) has attracted increasing attention due to their potential applications in various areas in recent years. In this study, a facile conversion from aggregation-caused quenching (ACQ) to aggregation-induced emission (AIE) was achieved by an efficient regioisomerization strategy based on the rofecoxib scaffold. Two compounds, named PYR2 and PYR4, were identified as regioisomers of rofecoxib derivatives to show dramatically different fluorescent properties. Compound PYR2 with an ortho-substituted piperidine group showed typical AIE activity while compound PYR4 with a para-piperidine group exhibited typical ACQ behavior. Notably, compound PYR2 showed polymorphism with two forms of crystals. It was also endowed with reversible mechanochromic luminescence and acidochromic properties. The different fluorescent properties were elucidated by UV/Vis absorption spectroscopy, powder X-ray diffraction, differential scanning calorimetry, and thermogravimetric analyses. Its application as a security ink and in lipid droplets imaging have been demonstrated.

Development of Rofecoxib-Based Fluorophores from ACQ to AIE by Positional Regioisomerization.

The invention discloses a surface amine functionalized rare earth doped barium fluochloride nanometer fluorescence labeling material and a preparation method thereof, and relates to a surface functionalized water soluble nanometer fluorescence labeling material preparation The formula of the barium fluochloride nanometer fluorescence labeling material prepared by the method of the present invention is XLn -(1-x)BaFCl (Ln=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb; X=0-60 mol% ) According to the preparation method, polypropylenimine is adopted as a surfactant, and a one-step reaction is performed to prepare the surface amine functionalized water soluble rare earth doped barium fluochloride nanometer fluorescence labeling material, wherein the results of transmission electron microscope, infrared absorption spectrum, gravitational thermal analysis and other test methods show that the polypropylenimine is effectively coated on the surfaces of the nanoparticles The prepared nanometer powder has good solubility; with the amino groups on the surface, the basis is established for the further combination of the biological molecules; with the rare earth ion doping, the material can achieve the purposes of strong luminous intensity, and rare earth ion fluorescence emission with long fluorescence lifetime

Surface amine functionalized rare earth doped BaFCl nanometer fluorescence labeling material and preparation method thereof

Aggregation-induced emission (AIE) has attracted much attention in the past 2 decades. To develop novel AIE-active materials, ACQ-to-AIE transformation via regioisomerization is one of the most straightforward method. However, most of the reported ACQ-to-AIE transformations are achieved by migrating bulky units. In this work, a facile conversion was realized by migrating a small pyrrolidinyl group from para- to ortho-position on the rofecoxib scaffold. As a result, a pair of new isomers named MOX2 and MOX4 exhibited AIE behavior and ACQ activity, respectively. Moreover, MOX2 also showed solvatochromic, mechanochromic, and acidochromic properties with reversible multi-stimulus behavior. Single crystal X-ray analysis of MOX2 revealed that the molecular conformation and its packing mode were responsible for the AIE emission behavior. Further investigation indicated that MOX2 showed high lipid droplets staining selectivity. Taken together, the current work not only provides a new design philosophy for achieving ACQ-to-AIE conversion by migrating a small pyrrolidinyl group but also presents a promising candidate MOX2 for potential applications such as in security ink, optical recording and biological applications.

/pdf/precise-molecular-design-of-a-pair-of-new-regioisomerized-1pcqr9js.pdf

Precise Molecular Design of a Pair of New Regioisomerized Fluorophores With Opposite Fluorescent Properties

The growing crisis of antibiotic resistance calls for advanced and sustainable antibacterial strategies. In the past few years, lanthanide‐doped upconversion nanoparticles (UCNPs) with unique photophysical properties have been innovatively explored for bacterial detection and therapy, and hold promise for alleviating challenges faced in the post‐antibiotic era. In this review, the interface engineering for the bacteria‐targeted UCNP nanoplatforms is highlighted, the principles and merits of various upconversion detection strategies are discussed, and the latest progress in UCNP‐based antibacterial applications are summarized, especially in deep‐tissue infection imaging and therapy. Finally, the remaining concerns and future efforts for practical applications are put forward. This review is expected to provide comprehensive guidance for diagnosing and combating bacterial infections based on advanced UCNP nanoplatforms.

Xueyuan Chen

Papers

Open type low-temperature high-resolution ratio laser spectrum test system

Development of Rofecoxib-Based Fluorophores from ACQ to AIE by Positional Regioisomerization.

Surface amine functionalized rare earth doped BaFCl nanometer fluorescence labeling material and preparation method thereof

Precise Molecular Design of a Pair of New Regioisomerized Fluorophores With Opposite Fluorescent Properties

Lanthanide Upconversion Nanoplatforms for Advanced Bacteria‐Targeted Detection and Therapy