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Xueyuan Chen

Bio: Xueyuan Chen is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Luminescence & Photon upconversion. The author has an hindex of 60, co-authored 234 publications receiving 15472 citations. Previous affiliations of Xueyuan Chen include Harvard University & Fuzhou University.


Papers
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TL;DR: By rational design of a core-shell structure with a set of lanthanide ions incorporated into separated layers at precisely defined concentrations, efficient upconversion emission can be realized through gadolinium sublattice-mediated energy migration for a wide range of Lanthanide activators without long-lived intermediary energy states.
Abstract: Photon upconversion is promising for applications such as biological imaging, data storage or solar cells. Here, we have investigated upconversion processes in a broad range of gadolinium-based nanoparticles of varying composition. We show that by rational design of a core-shell structure with a set of lanthanide ions incorporated into separated layers at precisely defined concentrations, efficient upconversion emission can be realized through gadolinium sublattice-mediated energy migration for a wide range of lanthanide activators without long-lived intermediary energy states. Furthermore, the use of the core-shell structure allows the elimination of deleterious cross-relaxation. This effect enables fine-tuning of upconversion emission through trapping of the migrating energy by the activators. Indeed, the findings described here suggest a general approach to constructing a new class of luminescent materials with tunable upconversion emissions by controlled manipulation of energy transfer within a nanoscopic region.

1,528 citations

Journal ArticleDOI
19 Jul 2010-Analyst
TL;DR: Recent developments in optical biolabeling and bio-imaging involving upconversion nanoparticles are reviewed, simultaneously bringing to the forefront the desirable characteristics, strengths and weaknesses of these luminescent nanomaterials.
Abstract: Upconversion refers to non-linear optical processes that convert two or more low-energy pump photons to a higher-energy output photon. After being recognized in the mid-1960s, upconversion has attracted significant research interest for its applications in optical devices such as infrared quantum counter detectors and compact solid-state lasers. Over the past decade, upconversion has become more prominent in biological sciences as the preparation of high-quality lanthanide-doped nanoparticles has become increasingly routine. Owing to their small physical dimensions and biocompatibility, upconversion nanoparticles can be easily coupled to proteins or other biological macromolecular systems and used in a variety of assay formats ranging from bio-detection to cancer therapy. In addition, intense visible emission from these nanoparticles under near-infrared excitation, which is less harmful to biological samples and has greater sample penetration depths than conventional ultraviolet excitation, enhances their prospects as luminescent stains in bio-imaging. In this article, we review recent developments in optical biolabeling and bio-imaging involving upconversion nanoparticles, simultaneously bringing to the forefront the desirable characteristics, strengths and weaknesses of these luminescent nanomaterials.

1,284 citations

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TL;DR: These findings show great promise of K2TiF6:Mn(4+) as a commercial red phosphor in warm white LEDs, and open up new avenues for the exploration of novel non-rare-earth red emitting phosphors.
Abstract: Manganese-activated fluoride phosphors for high-efficacy warm white light-emitting diodes have been limited by low photoluminescence quantum yields. Here, Zhu et al. use an efficient cation exchange reaction to synthesize manganese phosphors with photoluminescence quantum yields as high as 98%.

1,046 citations

Journal ArticleDOI
TL;DR: A comprehensive survey of the latest advances made in developing lanthanide-doped inorganic nanoparticles as potential luminescent bioprobes covering areas from their fundamental chemical and physical features to bioapplications including controlled synthesis methodology, surface modification chemistry, optical spectroscopy, and their promising applications in diverse fields are provided.
Abstract: Lanthanide-doped inorganic nanoparticles possess superior physicochemical features such as long-lived luminescence, large antenna-generated Stokes or anti-Stokes shifts, narrow emission bands, high resistance to photobleaching and low toxicity, and thus are regarded as a new generation of luminescent bioprobes as compared to conventional molecular probes like organic dyes and lanthanide chelates. These functional nanoparticles, although most of their bulk counterparts were well studied previously, have attracted renewed interest for their biomedical applications in areas as diverse as biodetection, bioimaging, and disease diagnosis and therapeutics. In this review, we provide a comprehensive survey of the latest advances made in developing lanthanide-doped inorganic nanoparticles as potential luminescent bioprobes, which covers areas from their fundamental chemical and physical features to bioapplications including controlled synthesis methodology, surface modification chemistry, optical spectroscopy, and their promising applications in diverse fields, with an emphasis on heterogeneous and homogeneous in vitro biodetection of tumor markers and multimodal bioimaging of various tumor tissues. Some future prospects and challenges in this rapidly growing field are also summarized.

738 citations

Journal ArticleDOI
Wei Zheng1, Ping Huang1, Datao Tu1, En Ma1, Haomiao Zhu1, Xueyuan Chen1 
TL;DR: This review focuses on the most recent advances in the development of lanthanide-doped UCNPs as potential luminescent nano-bioprobes by means of the authors' customized lanthanides photophysics measurement platforms specially designed for upconversion luminescence.
Abstract: Lanthanide-doped upconversion nanoparticles (UCNPs) have attracted considerable interest due to their superior physicochemical features, such as large anti-Stokes shifts, low autofluorescence background, low toxicity and high penetration depth, which make them extremely suitable for use as alternatives to conventional downshifting luminescence bioprobes like organic dyes and quantum dots for various biological applications. A fundamental understanding of the photophysics of lanthanide-doped UCNPs is of vital importance for discovering novel optical properties and exploring their new applications. In this review, we focus on the most recent advances in the development of lanthanide-doped UCNPs as potential luminescent nano-bioprobes by means of our customized lanthanide photophysics measurement platforms specially designed for upconversion luminescence, which covers from their fundamental photophysics to bioapplications, including electronic structures (energy levels and local site symmetry of emitters), excited-state dynamics, optical property designing, and their promising applications for in vitro biodetection of tumor markers. Some future prospects and efforts towards this rapidly growing field are also envisioned.

698 citations


Cited by
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2,877 citations

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TL;DR: EDS results confirmed a systematic increase of Eu content in the as-prepared samples with the increase of nominal europiumcontent in the reaction solution, and crystallinity and crystallite size of the titania particles decreased gradually.
Abstract: 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.

2,378 citations

Journal ArticleDOI
TL;DR: This paper presents a meta-modelling study of the response of the immune system to chemotherapy and its applications in the context of central nervous system disorders.
Abstract: 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

2,194 citations

Journal ArticleDOI
TL;DR: 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.
Abstract: 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.

1,999 citations

Journal ArticleDOI
TL;DR: Applications in Theranostics Guanying Chen,*,†,‡ Hailong Qiu,*,‡ and Xiaoyuan Chen.
Abstract: 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

1,994 citations