Co-reporter:Haixia Li, Hao Dong, Mingming Yu, Chunxia Liu, Zhanxian Li, Liuhe Wei, Ling-Dong Sun, and Hongyan Zhang
Analytical Chemistry September 5, 2017 Volume 89(Issue 17) pp:8863-8863
Publication Date(Web):July 14, 2017
DOI:10.1021/acs.analchem.7b01324
It is crucial for cell physiology to keep the homeostasis of pH, and it is highly demanded yet challenging to develop luminescence resonance energy transfer (LRET)-based near-infrared (NIR) ratiometric luminescent sensor for the detection of pH fluctuation with NIR excitation. As promising energy donors for LRET, upconversion nanoparticles (UCNPs) have been widely used to fabricate nanosensors, but the relatively low LRET efficiency limits their application in bioassay. To improve the LRET efficiency, core/shell/shell structured β-NaGdF4@NaYF4:Yb,Tm@NaYF4 UCNPs were prepared and decorated with hemicyanine dyes as an LRET-based NIR ratiometric luminescent pH fluctuation-nanosensor for the first time. The as-developed nanosensor not only exhibits good antidisturbance ability, but it also can reversibly sense pH and linearly sense pH in a range of 6.0–9.0 and 6.8–9.0 from absorption and upconversion emission spectra, respectively. In addition, the nanosensor displays low dark toxicity under physiological temperature, indicating good biocompatibility. Furthermore, live cell imaging results revealed that the sensor can selectively monitor pH fluctuation via ratiometric upconversion luminescence behavior.
Co-reporter:Hao Dong, Ling-Dong Sun, Wei Feng, Yuyang Gu, Fuyou Li, and Chun-Hua Yan
ACS Nano March 28, 2017 Volume 11(Issue 3) pp:3289-3289
Publication Date(Web):February 26, 2017
DOI:10.1021/acsnano.7b00559
Optical encoding together with color multiplexing benefits on-site detection, and enriching the components with narrow emissions from lanthanide could greatly increase the coding density. Here, we show a typical example to combine emission color and lifetime that are simultaneously integrated in a single lanthanide nanoparticle. With the multicompartment core/shell structure, the nanoparticles can activate different emitting pathways under varied excitation. This enables the nanoparticles to generate versatile excitation orthogonalized upconversion luminescence in both emission colors and lifetimes. As a typical example, green emission of Er3+ and blue emission of Tm3+ can be triggered with 808 and 980 nm lasers, respectively. Moreover, with incorporation of Tb3+, not only is emission from Tb3+ introduced but also the lifetime difference of 0.13 ms (Er3+) and 3.6 ms (Tb3+) is yielded for the green emission, respectively. Multiplexed fingerprint imaging and time-gated luminescence imaging were achieved in wavelength and lifetime dimensions. The spectral and lifetime encoding ability from lanthanide luminescence greatly broadens the scope of luminescent materials for optical multiplexing studies.Keywords: core/shell nanoparticle; energy transfer; lanthanide; multiplexing; upconversion;
Co-reporter:Ligang Wang, Yuan Huang, Aashir Waleed, Ke Wu, Cong Lin, Zhengxu Wang, Guanhaojie Zheng, Zhiyong Fan, Junliang Sun, Huanping Zhou, Ling-Dong Sun, and Chun-Hua Yan
ACS Applied Materials & Interfaces August 9, 2017 Volume 9(Issue 31) pp:25985-25985
Publication Date(Web):July 13, 2017
DOI:10.1021/acsami.7b05875
Among the various building blocks beyond polycrystalline thin films, perovskite wires have attracted extensive attention for potential applications including nanolasers, waveguides, field-effect transistors, and more. In this work, millimeter-scale lead iodine-based perovskite wires employing various A-site substitutions, namely, Cs, methylammonium (MA), and formamidinium (FA), have been synthesized via a new type solution method with nearly 100% yield. All of the three millimeter scale perovskite wires (MPWs) compositions exhibit relatively high quality, and CsPbI3 is proven to be monocrystalline along its entire length. Furthermore, the growth thermodynamics of the APbI3 MPWs with respect to A-site cation effect were studied thoroughly by various characterization techniques. Finally, single MPW photodetectors have been fabricated utilizing the APbI3 MPWs for studying the photoconductive properties, which show different sensitivities under illumination. This systematic synthesis method of solution-processed APbI3 (Cs, MA, and FA) MPWs reveals a wide spectrum of additives with different coordination capability that mediates perovskite materials growth. It proved to serve as a new parameter that further aids in the rational process of the polycrystalline organic/inorganic hybrids materials. These MPWs also have the potential to open up new opportunities for integrated nanoelectronics ranging from the nanometer through millimeter length scales.Keywords: monocrystalline; perovskite; photodetector; thermodynamics; wire;
Co-reporter:Xiao-Yu Zheng, Kai Zhao, Jinglong Tang, Xin-Yu Wang, Lin-Dong Li, Nai-Xiu Chen, Yan-Jie Wang, Shuo Shi, Xiaodong Zhang, Sivakumar Malaisamy, Ling-Dong Sun, Xiaoying Wang, Chunying Chen, and Chun-Hua Yan
ACS Nano April 25, 2017 Volume 11(Issue 4) pp:3642-3642
Publication Date(Web):March 28, 2017
DOI:10.1021/acsnano.6b07959
Magnetic resonance imaging contrast agents with both significantly enhanced relaxivity and minimal safety risk are of great importance for sensitive clinical diagnosis, but have rarely been reported. Herein, we present a simple strategy to improve relaxivity by introducing surface ligands with strong interaction to water molecules. As a proof of concept, NaGdF4 nanoparticles (NPs) capped by poly(acrylic acid) (PAA) show superior relaxivity to those capped by polyethylenimine and polyethylene glycol, which is attributed to the strong hydrogen-bond capacity of PAA to water molecules as revealed by theoretical calculation. Furthermore, benefiting from PAA and ultrasmall particle size, Gd-dots, namely PAA-capped GdOF NPs (2.1 ± 0.2 nm), are developed as a high-performance contrast agent, with a remarkable ionic relaxivity of ∼75 mM–1 s–1 in albumin solution at 0.5 T. These Gd-dots also exhibit efficient renal clearance with <3% of injected amount left 12 h post-injection. Ultrasensitive MR renography achieved with Gd-dots strongly suggests their great potential for practical applications.Keywords: contrast agents; ligand effects; magnetic resonance imaging; nanoparticles; rare earths;
Co-reporter:Bolong Huang;Mingzi Sun;Alan William Dougherty;Hao Dong;Yue-Jiao Xu;Chun-Hua Yan
Nanoscale (2009-Present) 2017 vol. 9(Issue 46) pp:18490-18497
Publication Date(Web):2017/11/30
DOI:10.1039/C7NR06729A
Unravelling upconversion (UC) energy transfer mechanisms is significant for designing novel efficient anti-Stokes phosphors. We have studied the correlation of different lanthanide dopants within Er3+-self-sensitized core@shell upconversion nanoparticles (UCNPs). Here, our focus will be on high-concentration dopants that are able to sufficiently produce the clustering effect, especially within the interplay between Er3+ and Yb3+. We demonstrate that whatever the amount of the self-sensitizer (e.g., Er3+), abnormal absorption enhancement will occur as long as Yb3+ clusters are present. This effect originates from the substantial energy transfer between Yb3+–Yb3+ clusters despite the increased energy transfer from Yb3+ to Er3+. Therefore, the energy transfer efficiency is still constrained. However, we conversely used one of the aforementioned quench-paths of UC energy transfer to easily transfer the energy from the in-shell shell layer to the in-core area with the assistance of the energy potential reservoir, which was given by the homogeneous core@shell band offset at the interface region. Indirectly, we actualize the Er3+ UC luminescence with self-sensitization through an extended energy transfer path. This work provides a solid support and analytic theory for unraveling the energy transfer mechanism from recent works on Er3+ self-sensitized UC luminescence.
Co-reporter:Mu Lin;Liqun Kang;Jun Gu;Linxiu Dai;Shengbo Tang;Tao Zhang
Nano Research 2017 Volume 10( Issue 3) pp:922-932
Publication Date(Web):2017 March
DOI:10.1007/s12274-016-1350-0
The transition from homogeneous to heterogeneous synthetic chemistry enabled by nanocatalysts necessitates investigations of the reaction mechanism and structure-activity relationships for inorganic nanoparticles and organic substrates. Herein, we report that hydrothermally synthesized ruthenium nanoparticles performed differently in the Se–Se bond activation and selenylation of heterocycles, exhibiting a volcano-shaped relationship between catalytic activity and composition. A synergistic effect was observed for Ru-RuOx nanocatalysts, with numerous characterizations and density functional theory (DFT) calculations suggesting that a PhSeSePh molecule can initially be adsorbed on the metallic Ru sites and cleaved into two PhSe* species, which subsequently migrate to RuOx sites and react with the nucleophile to achieve the selenylation of heterocycles.
Co-reporter:Mu Lin;Lin-Xiu Dai;Jun Gu;Li-Qun Kang;Yu-Hao Wang;Rui Si;Ze-Qiong Zhao;Wen-Chi Liu;Xuefeng Fu;Ya-Wen Zhang;Chun-Hua Yan
RSC Advances (2011-Present) 2017 vol. 7(Issue 53) pp:33078-33085
Publication Date(Web):2017/06/29
DOI:10.1039/C7RA05726A
For converting a homogeneous synthetic chemistry reaction to a heterogeneous one, using nanocatalysts, it is essential to investigate the underlying principles and the associated dominant factors of methodologies between inorganic nanoparticles and organic substrates. Here it is reported that novel, hydrothermally synthesized ruthenium (Ru) nanoparticles performed differently in molecular oxygen activation via single electron transfer for cross-dehydrogenative-coupling reactions, following a volcano shaped relationship between their oxidation levels and catalytic activity. Characterizations and a systematic mechanism study indicated that Ru3+ sites contributed to more superoxo- or peroxo-like species being formed from molecular oxygen on Ru nanoparticles with a moderate oxidation level, and the Ru3+ were the highly active species which accelerate this cross-dehydrogenative-coupling reaction via single electron transfer.
Co-reporter:Qing-Song Qin;Pei-Zhi Zhang;Shuo Shi;Nai-Xiu Chen;Hao Dong;Xiao-Yu Zheng;Le-Min Li;Chun-Hua Yan
Nanoscale (2009-Present) 2017 vol. 9(Issue 14) pp:4660-4664
Publication Date(Web):2017/04/06
DOI:10.1039/C7NR00606C
Lanthanide-doped luminescent nanoparticles with both emission and excitation in the near-infrared (NIR-to-NIR) region hold great promise for bioimaging. Herein, core@shell structured LiLuF4:Nd@LiLuF4 (named as Nd@Lu) nanoparticles (NPs) with highly efficient NIR emission were developed for high-performance in vivo bioimaging. Strikingly, the absolute quantum yield of Nd@Lu NPs reached as high as 32%. After coating with polyethylene glycol (PEG), the water-dispersible Nd@Lu NPs showed good bio-compatibility and low toxicity. With efficient NIR emission, the Nd@Lu NPs were clearly detectable in tissues at depths of up to 20 mm. In addition, long-term in vivo biodistribution with a high signal-to-noise ratio of 25.1 was distinctly tracked upon an ultralow-power-density excitation (10 mW cm−2) of 732 nm for the first time.
Co-reporter:Ke Wu;Liang Zhou;Chun-Jiang Jia;Chun-Hua Yan
Materials Chemistry Frontiers 2017 vol. 1(Issue 9) pp:1754-1763
Publication Date(Web):2017/08/23
DOI:10.1039/C7QM00244K
Exploring high-performance catalysts has always been a general concern for promoting extended heterocatalysis reactions. Here, Pt embedded highly-porous CeO2 hollow sphere (Pt/CeO2 HS) composites are developed by a one-pot template-free solvothermal method. Evolution mechanism studies unravel that the Pt/CeO2 HS composites are derived from a self-assembly–reduction–Ostwald ripening process, where Pt nanoparticles (Pt NPs) are embedded into ceria mesoporous hollow spheres. The as-developed embedment strategy is more facile, sustainable and cost-effective than conventional deposition approaches, ensuring the precise control of the location, distribution, and uniformity of Pt NPs throughout the outer shell of hollow spherical CeO2. Importantly, the Pt NP embedding process could be determined to play a key role in creating oxygen vacancies and activating surface chemisorbed oxygen. Besides that, the aggregation of Pt NPs can be efficiently inhibited in the Pt/CeO2 HS composites, and more active sites should be involved in catalytic reactions. All these advantages contribute to the strikingly improved performance as well as excellent stability of the Pt/CeO2 HS composites toward CO oxidation reaction compared with mesoporous CeO2 nanospheres (CeO2 NS) and Pt/CeO2 NS reference catalysts. These findings present a decent protocol for desgining noble metal/oxide hollow structural composites in heterogeneous catalysis.
Co-reporter:Hao Dong, Ling-Dong Sun, Ye-Fu Wang, Jia-Wen Xiao, Datao Tu, Xueyuan Chen and Chun-Hua Yan
Journal of Materials Chemistry A 2016 vol. 4(Issue 19) pp:4186-4192
Publication Date(Web):31 Mar 2016
DOI:10.1039/C6TC00413J
Exploring novel lanthanide-activated upconversion nanoparticles with distinctive spectral fingerprints and emission lifetimes has long been a great concern for extended optical applications. Herein, we report the study of photon upconversion emissions in Yb3+–Tb3+ and Yb3+–Eu3+ activated nanoparticles with near-infrared excitation. In these nanoparticles, a high content of Yb3+ is required for the simultaneous excitation of two Yb3+ ions, yielding a Yb3+ dimer with a higher excited energy to upconvert photons onto Tb3+ and Eu3+. The optimum doping concentration of Yb3+ ions for Yb3+–Tb3+ and Yb3+–Eu3+ pairs was determined to be 80% and 60%, respectively, which are much higher than that of Yb3+–Er3+/Tm3+ pairs. Notably, the upconversion emission lifetime of the as-prepared nanoparticles was prolonged to 2.3 ms (Tb3+) and 4.0 ms (Eu3+), respectively. Through the epitaxial growth of a Nd3+ doped shell layer, the upconversion emissions of Tb3+ and Eu3+ were intensified 25-fold. At the same time, an extra excitation band in the shorter near-infrared region from Nd3+ at 808 nm was achieved. Moreover, the emissions of Tm3+ were employed to compensate for those of Tb3+ and Eu3+ for multicolor emissions. These results highlight the upconversion emissions of Tb3+ and Eu3+ for potential multicolor imaging and multiplexed detection applications.
Co-reporter:Guang-Ming Lyu, Yan-Jie Wang, Xue Huang, Huai-Yuan Zhang, Ling-Dong Sun, Yan-Jun Liu and Chun-Hua Yan
Nanoscale 2016 vol. 8(Issue 15) pp:7923-7932
Publication Date(Web):09 Mar 2016
DOI:10.1039/C6NR00826G
Oxidative stress plays a key role in the occurrence and development of diabetes. With their unique redox properties, CeO2 nanoparticles (nanoceria) exhibit promising potential for the treatment of diabetes resulting from oxidative stress. Here, we develop a novel preparation of hydrophilic CeO2 nanocubes (NCs) with two different sizes (5 nm and 25 nm) via an acetate assisted hydrothermal method. Dynamic light scattering, zeta potential measurements and thermogravimetric analyses were utilized to investigate the changes in the physico-chemical characteristics of CeO2 NCs when exposed to in vitro cell culture conditions. CCK-8 assays revealed that the CeO2 NCs did not impair cell proliferation in the pancreatic β-cell line INS-1 at the highest dose of 200 μg mL−1 over the time scale of 72 h, while being able to protect INS-1 cells from H2O2-induced cytotoxicity even after protein adsorption. It is also noteworthy that nanoceria with a smaller hydrodynamic radius exhibit stronger antioxidant and anti-apoptotic effects, which is consistent with their H2O2 quenching capability in biological systems. These findings suggest that nanoceria can be used as an excellent antioxidant for controlling oxidative stress-induced pancreatic β-cell damage.
Co-reporter:Feng Qin;Tian Zhao;Ruibin Jiang;Nina Jiang;Qifeng Ruan;Jianfang Wang;Chun-Hua Yan;Hai-Qing Lin
Advanced Optical Materials 2016 Volume 4( Issue 1) pp:76-85
Publication Date(Web):
DOI:10.1002/adom.201500496
Co-reporter:Yang Li, Jinglong Tang, Dong-Xu Pan, Ling-Dong Sun, Chunying Chen, Ying Liu, Ye-Fu Wang, Shuo Shi, and Chun-Hua Yan
ACS Nano 2016 Volume 10(Issue 2) pp:2766
Publication Date(Web):January 21, 2016
DOI:10.1021/acsnano.5b07873
Upconversion (UC) luminescent lanthanide nanoparticles (LNPs) are expected to play an important role in imaging and photodynamic therapy (PDT) in vitro and in vivo. However, with the absorption of UC emissions by photosensitizers (PSs) to generate singlet oxygen (1O2) for PDT, the imaging signals from LNPs are significantly weakened. It is important to activate another imaging route to track the location of the LNPs during PDT process. In this work, Nd3+-sensitized LNPs with dual-band visible and near-infrared (NIR) emissions under single 808 nm excitation were reported to address this issue. The UC emissions in green could trigger covalently linked rose bengal (RB) molecules for efficient PDT, and NIR emissions deriving from Yb3+ and magnetic resonance imaging (MRI) were used for imaging simultaneously. Notably, the designed therapeutic platform could further effectively avoid the overheating effect induced by the laser irradiation, due to the minimized absorption of biological media at around 808 nm. TdT-mediated dUTP nick end labeling (TUNEL) assay showed serious cell apoptosis in the tumor after PDT for 2 weeks, leading to an effective tumor inhibition rate of 67%. Benefit from the PDT, the tumor growth-induced liver and spleen burdens were largely attenuated, and the liver injury was also alleviated. More importantly, pulmonary and hepatic tumor metastases were significantly reduced after PDT. The Nd3+-sensitized LNPs provide a multifunctional nanoplatform for NIR light-assisted PDT with minimized heating effect and an effective inhibition of tumor growth and metastasis.Keywords: Nd3+-sensitized lanthanide nanoparticles; NIR imaging; photodynamic therapy; tumor metastasis; upconversion emissions;
Co-reporter:Hao Dong, Shuo-Ren Du, Xiao-Yu Zheng, Guang-Ming Lyu, Ling-Dong Sun, Lin-Dong Li, Pei-Zhi Zhang, Chao Zhang, and Chun-Hua Yan
Chemical Reviews 2015 Volume 115(Issue 19) pp:10725
Publication Date(Web):July 7, 2015
DOI:10.1021/acs.chemrev.5b00091
Co-reporter:Hao Dong, Ling-Dong Sun and Chun-Hua Yan
Chemical Society Reviews 2015 vol. 44(Issue 6) pp:1608-1634
Publication Date(Web):22 Sep 2014
DOI:10.1039/C4CS00188E
Lanthanide pairs, which can upconvert low energy photons into higher energy photons, are promising for efficient upconversion emission. A typical system with Yb3+ as a sensitizer can convert short NIR into visible/ultraviolet light via energy transfer between lanthanide ions. Such upconverting nanocrystals doped with lanthanide ions have found significant potential in bioimaging, photochemical reactions and energy conversion. This review presents a fundamental understanding of energy transfer in lanthanide-supported photon upconversion. We introduce the emerging progress in excitation selection based on the energy transfer within lanthanide ions or activation from antennae, with an outlook in the development and applications of the lanthanide upconversion emissions.
Co-reporter:Ling Wang;Hao Dong;Yannian Li;Rui Liu;Ye-Fu Wang;Hari Krishna Bisoyi;Chun-Hua Yan;Quan Li
Advanced Materials 2015 Volume 27( Issue 12) pp:2065-2069
Publication Date(Web):
DOI:10.1002/adma.201405690
Co-reporter:Hao Dong; Ling-Dong Sun; Ye-Fu Wang; Jun Ke; Rui Si; Jia-Wen Xiao; Guang-Ming Lyu; Shuo Shi;Chun-Hua Yan
Journal of the American Chemical Society 2015 Volume 137(Issue 20) pp:6569-6576
Publication Date(Web):May 4, 2015
DOI:10.1021/jacs.5b01718
Efficient tailoring of upconversion emissions in lanthanide-doped nanocrystals is of great significance for extended optical applications. Here, we present a facile and highly effective method to tailor the upconversion selectivity by engineering the local structure of lanthanides in NaxREF3+x nanocrystals. The local structure engineering was achieved through precisely tuning the composition of nanocrystals, with different [Na]/[RE] ([F]/[RE]) ratio. It was found that the lattice parameter as well as the coordination number and local symmetry of lanthanides changed with the composition. A significant difference in the red to green emission ratio, which varied from 1.9 to 71 and 1.6 to 116, was observed for NaxYF3+x:Yb,Er and NaxGdF3+x:Yb,Er nanocrystals, respectively. Moreover, the local structure-dependent upconversion selectivity has been verified for NaxYF3+x:Yb,Tm nanocrystals. In addition, the local structure induced upconversion emission from Er3+ enhanced 9 times, and the CaF2 shell grown epitaxially over the nanocrystals further promoted the red emission by 450 times, which makes it superior as biomarkers for in vivo bioimaging. These exciting findings in the local structure-dependent upconversion selectivity not only offer a general approach to tailoring lanthanide related upconversion emissions but also benefit multicolor displays and imaging.
Co-reporter:Yan-Jie Wang, Hao Dong, Guang-Ming Lyu, Huai-Yuan Zhang, Jun Ke, Li-Qun Kang, Jia-Li Teng, Ling-Dong Sun, Rui Si, Jing Zhang, Yan-Jun Liu, Ya-Wen Zhang, Yun-Hui Huang and Chun-Hua Yan
Nanoscale 2015 vol. 7(Issue 33) pp:13981-13990
Publication Date(Web):09 Jul 2015
DOI:10.1039/C5NR02588E
Due to their excellent anti-oxidation performance, CeO2 nanoparticles receive wide attention in pharmacological application. Deep understanding of the anti-oxidation mechanism of CeO2 nanoparticles is extremely important to develop potent CeO2 nanomaterials for anti-oxidation application. Here, we report a detailed study on the anti-oxidation process of CeO2 nanoparticles. The valence state and coordination structure of Ce are characterized before and after the addition of H2O2 to understand the anti-oxidation mechanism of CeO2 nanoparticles. Adsorbed peroxide species are detected during the anti-oxidation process, which are responsible for the red-shifted UV-vis absorption spectra of CeO2 nanoparticles. Furthermore, the coordination number of Ce in the first coordination shell slightly increased after the addition of H2O2. On the basis of these experimental results, the reactivity of coordination sites for peroxide species is considered to play a key role in the anti-oxidation performance of CeO2 nanoparticles. Furthermore, we present a robust method to engineer the anti-oxidation performance of CeO2 nanoparticles through the modification of the defect state and reducibility by doping with Gd3+. Improved anti-oxidation performance is also observed in cell culture, where the biocompatible CeO2-based nanoparticles can protect INS-1 cells from oxidative stress induced by H2O2, suggesting the potential application of CeO2 nanoparticles in the treatment of diabetes.
Co-reporter:Xiao-Yu Zheng;Tao Zheng;Hao Dong;Yang Li;Ye-Fu Wang
Science Bulletin 2015 Volume 60( Issue 12) pp:1092-1100
Publication Date(Web):2015 June
DOI:10.1007/s11434-015-0802-3
Aiming at improving the sensitivity and accuracy of diagnosis, the combination of magnetic resonance imaging (MRI) and X-ray computed tomography (CT) in a single probe is in urgent need. Here, we report the development of polyacrylic acid (PAA)-capped GdF3 nanoplates (NPs) as novel MRI and CT dual-mode contrast agents (CAs) with high longitudinal relaxivity (r1) and large X-ray attenuation coefficient. Uniform GdF3 rhombic NPs were fabricated by controlling reaction conditions and introducing dopants. The average size of GdF3 NPs is (10.6 ± 1.1) nm in long diagonal, (7.0 ± 0.8) nm in short diagonal, and (4.2 ± 1.2) nm in thickness. Ligand-exchange treatment was performed to render the NPs water-dispersible. The r1 of PAA-capped GdF3 NPs (15.8 L/(mmol s)) is four times higher than that of clinically used Gd-DTPA. We suppose that the high r1 value originates from the construction of two-dimensional (2D) nanostructures, which endows nanocrystals with larger surface areas and longer rotational correlation time than those of sphere nanostructures with the same volume. The CT contrast enhancement ability of PAA-capped GdF3 NPs was evaluated in comparison with clinically used Iohexol. The above results suggest that the PAA-capped GdF3 NPs could serve as CAs for MRI and CT dual-mode imaging.
Co-reporter:Ling Wang ; Hao Dong ; Yannian Li ; Chenming Xue ; Ling-Dong Sun ; Chun-Hua Yan ;Quan Li
Journal of the American Chemical Society 2014 Volume 136(Issue 12) pp:4480-4483
Publication Date(Web):March 5, 2014
DOI:10.1021/ja500933h
Adding external, dynamic control to self-organized superstructures with desired functionalities is an important leap necessary in leveraging the fascinating molecular systems for applications. Here, the new light-driven chiral molecular switch and upconversion nanoparticles, doped in a liquid crystal media, were able to self-organize into an optically tunable helical superstructure. The resulting nanoparticle impregnated helical superstructure was found to exhibit unprecedented reversible near-infrared (NIR) light-guided tunable behavior only by modulating the excitation power density of a continuous-wave NIR laser (980 nm). Upon irradiation by the NIR laser at the high power density, the reflection wavelength of the photonic superstructure red-shifted, whereas its reverse process occurred upon irradiation by the same laser but with the lower power density. Furthermore, reversible dynamic NIR-light-driven red, green, and blue reflections in a single thin film, achieved only by varying the power density of the NIR light, were for the first time demonstrated.
Co-reporter:Jia-Wen Xiao, Shi-Xuan Fan, Feng Wang, Ling-Dong Sun, Xiao-Yu Zheng and Chun-Hua Yan
Nanoscale 2014 vol. 6(Issue 8) pp:4345-4351
Publication Date(Web):28 Jan 2014
DOI:10.1039/C3NR06843A
Nanoparticle (NP) mediated photothermal effect shows great potential as a noninvasive method for cancer therapy treatment, but the development of photothermal agents with high photothermal conversion efficiency, small size and good biocompatibility is still a big challenge. Herein, we report Pd NPs with a porous structure exhibiting enhanced near infrared (NIR) absorption as compared to Pd nanocubes with a similar size (almost two-fold enhancement with a molar extinction coefficient of 6.3 × 107 M−1 cm−1), and the porous Pd NPs display monotonically rising absorbance from NIR to UV-Vis region. When dispersed in water and illuminated with an 808 nm laser, the porous Pd NPs give a photothermal conversion efficiency as high as 93.4%, which is comparable to the efficiency of Au nanorods we synthesized (98.6%). As the porous Pd NPs show broadband NIR absorption (650–1200 nm), this allows us to choose multiple laser wavelengths for photothermal therapy. In vitro photothermal heating of HeLa cells in the presence of porous Pd NPs leads to 100% cell death under 808 nm laser irradiation (8 W cm−2, 4 min). For photothermal heating using 730 nm laser, 70% of HeLa cells were killed after 4 min irradiation at a relative low power density of 6 W cm−2. These results demonstrated that the porous Pd nanostructure is an attractive photothermal agent for cancer therapy.
Co-reporter:Feng Wang ; Chuanhao Li ; Huanjun Chen ; Ruibin Jiang ; Ling-Dong Sun ; Quan Li ; Jianfang Wang ; Jimmy C. Yu ;Chun-Hua Yan
Journal of the American Chemical Society 2013 Volume 135(Issue 15) pp:5588-5601
Publication Date(Web):March 25, 2013
DOI:10.1021/ja310501y
The efficient use of solar energy has received wide interest due to increasing energy and environmental concerns. A potential means in chemistry is sunlight-driven catalytic reactions. We report here on the direct harvesting of visible-to-near-infrared light for chemical reactions by use of plasmonic Au–Pd nanostructures. The intimate integration of plasmonic Au nanorods with catalytic Pd nanoparticles through seeded growth enabled efficient light harvesting for catalytic reactions on the nanostructures. Upon plasmon excitation, catalytic reactions were induced and accelerated through both plasmonic photocatalysis and photothermal conversion. Under the illumination of an 809 nm laser at 1.68 W, the yield of the Suzuki coupling reaction was ∼2 times that obtained when the reaction was thermally heated to the same temperature. Moreover, the yield was also ∼2 times that obtained from Au–TiOx–Pd nanostructures under the same laser illumination, where a 25-nm-thick TiOx shell was introduced to prevent the photocatalysis process. This is a more direct comparison between the effect of joint plasmonic photocatalysis and photothermal conversion with that of sole photothermal conversion. The contribution of plasmonic photocatalysis became larger when the laser illumination was at the plasmon resonance wavelength. It increased when the power of the incident laser at the plasmon resonance was raised. Differently sized Au–Pd nanostructures were further designed and mixed together to make the mixture light-responsive over the visible to near-infrared region. In the presence of the mixture, the reactions were completed within 2 h under sunlight, while almost no reactions occurred in the dark.
Co-reporter:Hao Dong, Ling-Dong Sun and Chun-Hua Yan
Nanoscale 2013 vol. 5(Issue 13) pp:5703-5714
Publication Date(Web):16 Jan 2013
DOI:10.1039/C3NR34069D
With abundant energy levels of 4f electron configurations, trivalent lanthanide ions (Ln3+) are endowed with unique and fascinating luminescent properties. Inheriting the native transition behaviour of the lanthanide ions, Ln3+ based nanomaterials have aroused great interest for a wide range of applications, including lighting and displays, optical fibers and amplifiers, responsive luminescent stains for biomedical analysis, in vivo and in vitro imaging, and enhancement for silicon solar cell devices. It should be noted that the application depends completely on the corresponding luminescent behaviour. To deepen the understanding of the luminescent mechanism is important for the developing of the field and the design of new Ln3+ based luminescent materials toward applications. In this review, we focused mainly on the recent developments on upconversion (UC) emission studies. Firstly, the emphasis was put on the introduction of basic luminescent properties of Ln3+ with f–f transitions, and then the corresponding mechanisms and properties of UC emission were discussed in detail, the potential researches with respect to UC mechanisms and properties were finally outlined.
Co-reporter:Tao Zheng, Ling-Dong Sun, Jia-Cai Zhou, Wei Feng, Chao Zhang and Chun-Hua Yan
Chemical Communications 2013 vol. 49(Issue 51) pp:5799-5801
Publication Date(Web):07 Feb 2013
DOI:10.1039/C3CC39108F
Monodispersed nanocrystals (NCs) can form ordered and functional binary superlattices. A variety of functional binary nanocrystal superlattices (BNSLs) and bilayer assemblies based on lanthanide-doped NaREF4 (RE = Y, Gd) were constructed with different assembly methods. These assemblies are attractive for applications in photonics as they display multicolor upconversion (UC) emissions.
Co-reporter:Chao Zhang, An-Xiang Yin, Ruibin Jiang, Jie Rong, Lu Dong, Tian Zhao, Ling-Dong Sun, Jianfang Wang, Xing Chen, and Chun-Hua Yan
ACS Nano 2013 Volume 7(Issue 5) pp:4561
Publication Date(Web):April 29, 2013
DOI:10.1021/nn401266u
Food safety is a constant concern for humans. Besides adulteration and contamination, another major threat comes from the spontaneous spoilage of perishable products, which is basically inevitable and highly dependent on the temperature history during the custody chain. For advanced quality control and assessment, time–temperature indicators (TTIs) can be deployed to document the temperature history. However, the use of TTIs is currently limited by either relatively high cost or poor programmability. Here we describe a general, kinetically programmable, and cost-efficient TTI protocol constructed from plasmonic nanocrystals. We present proof-of-principle demonstrations that our TTI can be specifically tailored and thus used to track perishables, dynamically mimic the deteriorative processes therein, and indicate product quality through sharp-contrast multicolor changes. The flexible programmability of our TTI, combined with its substantially low cost and low toxicity, promises a general applicability to each single packaged item of a plethora of perishable products.Keywords: chronochromism; kinetic synchronicity; localized surface plasmon resonance; noble metal nanocrystals; perishables; time−temperature indicators
Co-reporter:Ye-Fu Wang, Gao-Yuan Liu, Ling-Dong Sun, Jia-Wen Xiao, Jia-Cai Zhou, and Chun-Hua Yan
ACS Nano 2013 Volume 7(Issue 8) pp:7200
Publication Date(Web):July 19, 2013
DOI:10.1021/nn402601d
Upconversion (UC) process in lanthanide-doped nanomaterials has attracted great research interest for its extensive biological applications in vitro and in vivo, benefiting from the high tissue penetration depth of near-infrared excitation light and low autofluorescence background. However, the 980 nm laser, typically used to trigger the Yb3+-sensitized UC process, is strongly absorbed by water in biological structures and could cause severe overheating effect. In this article, we report the extension of the UC excitation spectrum to shorter wavelengths, where water has lower absorption. This is realized by further introducing Nd3+ as the sensitizer and by building a core/shell structure to ensure successive Nd3+→Yb3+→activator energy transfer. The efficacy of this Nd3+-sensitized UC process is demonstrated in in vivo imaging, and the results confirmed that the laser-induced local overheating effect is greatly minimized.Keywords: excitation band extension; heating effect; in vivo imaging; upconversion
Co-reporter:Yi-Qun Zhang, Ling-Dong Sun, Wei Feng, Hao-Shuai Wu and Chun-Hua Yan
Nanoscale 2012 vol. 4(Issue 16) pp:5092-5097
Publication Date(Web):14 Jun 2012
DOI:10.1039/C2NR31177A
SnO2 nanorods with specific growth directions, [101] or [001], were fabricated on α-Fe2O3 substrates via a simple hydrothermal method. The growth behavior of SnO2 nanorods is facet-selective. Both {110} and {100} facets of α-Fe2O3 are favorable to direct the growth of SnO2 nanorods. The correlation between the crystallographic orientation of SnO2 and the facets of α-Fe2O3 is characterized by TEM observations and investigated on the basis of the interfacial lattice compatibility. Furthermore, the distribution and coordination of oxygen atoms at the interface of α-Fe2O3–SnO2 heterostructure are analyzed, which reveals that only slight deviations from their original equilibrium positions are allowed for the formation of heterogeneous interface. And this lower energy activated interfacial construction is beneficial to the feasibility and stability of heterostructures.
Co-reporter:Hao-Shuai Wu, Ling-Dong Sun, Huan-Ping Zhou and Chun-Huan Yan
Nanoscale 2012 vol. 4(Issue 10) pp:3242-3247
Publication Date(Web):20 Mar 2012
DOI:10.1039/C2NR30523B
This article reports a facile and controllable two-step method to construct TiO2–Pt@SiO2 nanocomposites. TiO2 nanoparticles (NPs), with small size and high surface energy, were synthesized by a solvothermal reaction process. The TiO2–Pt@SiO2 nanocomposites were fabricated by a reverse micro-emulsion method. SiO2 shell coated NPs were adopted for further photocatalytic reaction. Because of their small size and high surface energy, TiO2@SiO2 and TiO2–Pt@SiO2 nanocomposites show higher photocatalytic activity than commercial Degussa P25. Compared with TiO2@SiO2, TiO2–Pt@SiO2nanocomposites have improved photocatalytic activity due to the Pt induced spatial separation of electrons and holes. The silica shells not only maintain the structure of the nanocomposites but also prevent their aggregation during the photocatalytic reactions, which is highly important for the good durability of the photocatalyst. This strategy is simple, albeit efficient, and can be extended to the synthesis of other composites of noble metals. It has opened a new window for the construction of hetero-nanocomposites with high activity and durability, which would serve as excellent models in catalytic systems of both theoretical and practical interest.
Co-reporter:Feng Wang;Chuanhao Li; Ling-Dong Sun;Chun-Hu Xu; Jianfang Wang; Jimmy C. Yu; Chun-Hua Yan
Angewandte Chemie 2012 Volume 124( Issue 20) pp:4956-4960
Publication Date(Web):
DOI:10.1002/ange.201107376
Co-reporter:Dr. Feng Wang;Dr. Ling-Dong Sun;Jun Gu;Ye-Fu Wang;Dr. Wei Feng;Yi Yang;Dr. Jianfang Wang;Dr. Chun-Hua Yan
Angewandte Chemie 2012 Volume 124( Issue 35) pp:8926-8929
Publication Date(Web):
DOI:10.1002/ange.201203069
Co-reporter:Feng Wang;Chuanhao Li; Ling-Dong Sun;Chun-Hu Xu; Jianfang Wang; Jimmy C. Yu; Chun-Hua Yan
Angewandte Chemie International Edition 2012 Volume 51( Issue 20) pp:4872-4876
Publication Date(Web):
DOI:10.1002/anie.201107376
Co-reporter:Dr. Feng Wang;Dr. Ling-Dong Sun;Jun Gu;Ye-Fu Wang;Dr. Wei Feng;Yi Yang;Dr. Jianfang Wang;Dr. Chun-Hua Yan
Angewandte Chemie International Edition 2012 Volume 51( Issue 35) pp:8796-8799
Publication Date(Web):
DOI:10.1002/anie.201203069
Co-reporter:Ye-Fu Wang;Dr. Ling-Dong Sun;Jia-Wen Xiao;Dr. Wei Feng;Jia-Cai Zhou;Dr. Jie Shen ;Dr. Chun-Hua Yan
Chemistry - A European Journal 2012 Volume 18( Issue 18) pp:5558-5564
Publication Date(Web):
DOI:10.1002/chem.201103485
Abstract
Upconversion emissions from rare-earth nanoparticles have attracted much interest as potential biolabels, for which small particle size and high emission intensity are both desired. Herein we report a facile way to achieve NaYF4:Yb,Er@CaF2 nanoparticles (NPs) with a small size (10–13 nm) and highly enhanced (ca. 300 times) upconversion emission compared with the pristine NPs. The CaF2 shell protects the rare-earth ions from leaking, when the nanoparticles are exposed to buffer solution, and ensures biological safety for the potential bioprobe applications. With the upconversion emission from NaYF4:Yb,Er@CaF2 NPs, HeLa cells were imaged with low background interference.
Co-reporter:Ye-Fu Wang;Dr. Ling-Dong Sun;Jia-Wen Xiao;Dr. Wei Feng;Jia-Cai Zhou;Dr. Jie Shen ;Dr. Chun-Hua Yan
Chemistry - A European Journal 2012 Volume 18( Issue 18) pp:
Publication Date(Web):
DOI:10.1002/chem.201290070
Co-reporter:Jia-Cai Zhou, Ling-Dong Sun, Jie Shen, Jian-Qin Gu and Chun-Hua Yan
Nanoscale 2011 vol. 3(Issue 5) pp:1977-1983
Publication Date(Web):01 Mar 2011
DOI:10.1039/C0NR01006E
A fluorescent-magnetic YPxV1−xO4:Eu@GdPO4 core/shell nanostructure was prepared by a two-step method. The YPxV1−xO4:Eu core was synthesized using a hydrothermal method, and it exhibits strong photoluminescence with the effective doping of phosphorus (P) and europium (Eu) into a YVO4 matrix. The hydrothermal process provides a hydrophilic and fresh surface for coating GdPO4 shell. As YPxV1−xO4:Eu and GdPO4 have the similar unit cell parameters, YPxV1−xO4:Eu nanoparticles (NPs) were favorably coated by an epitaxial growth of GdPO4 shell in aqueous phase. The core/shell nanostructure was identified by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The GdPO4 shell not only possesses the paramagnetic character, but also enhances the photoluminescence efficiency by blocking the non-radiative de-excitation from the VO43−groups to the surface quenching sites. These optical and magnetic properties promise outstanding fluorescent-magnetic bifunctional nanomaterials.
Co-reporter:Jia-Cai Zhou, Zheng-Lin Yang, Wei Dong, Ruo-Jin Tang, Ling-Dong Sun, Chun-Hua Yan
Biomaterials 2011 32(34) pp: 9059-9067
Publication Date(Web):
DOI:10.1016/j.biomaterials.2011.08.038
Co-reporter:Wei Feng, Ling-Dong Sun, and Chun-Hua Yan
Langmuir 2011 Volume 27(Issue 7) pp:3343-3347
Publication Date(Web):February 28, 2011
DOI:10.1021/la104743p
Assembly of nanoparticles is a promising route to fabricate devices from nanomaterials. Colloidal crystals are well-defined three-dimensional assemblies of nanoparticles with long-range ordered structures and crystalline symmetries. Here, we use a solvent evaporation induced assembly method to obtain colloidal crystals composed of polyhedral sodium rare earth fluoride nanoparticles. The building blocks exhibit the same crystalline orientation in each colloidal crystal as indicated in electron diffraction patterns. The driving force of the oriented assembly is ascribed to the facet-selected capping of oleic acid molecules on {110} facets of the nanoparticles, and the favorable coordination behavior of OA molecules is explained by the steric hindrance determined adsorption based on the studies of the surface atomic structure of nanocrystals and molecular mechanics simulation of OA molecules. The capping ligands also provide hydrophobic interactions between nanoparticles and further direct the oriented assembly process to construct a face-centered cubic structure. These results not only provide a new type of building block for colloidal crystals, but also clarify the important role of surface ligands, which determine the packed structure and orientations of nanoparticles in the assemblies.
Co-reporter:Jie Shen;Jia-Dan Zhu;Liu-He Wei;Hong-Fang Sun;Chun-Hua Yan
Advanced Functional Materials 2010 Volume 20( Issue 21) pp:3708-3714
Publication Date(Web):
DOI:10.1002/adfm.201001264
Abstract
Lanthanide nanoparticles (NPs), characterized by their large Stokes’ shifts, narrow emission bands and high photochemical stability, are promising candidates for optical probes in biological research. As a typical red emission material, Eu3+-doped YVO4 is investigated in pursuit of an integral methodology for Ln-based bioprobes. Assisted with phosphino-polyacrylic acid, YVO4:Eu NPs with a luminescent quantum yield of ca. 54% are synthesized via a one-pot hydrothermal reaction. The obtained NPs exhibit good water/buffer stability and feasible biomodification benefiting from the surface carboxylic acid groups. However, having an inorganic core of ca. 20 nm, these NPs do not affect the conformation of surface conjugated proteins (bovine serum albumin), as confirmed with the circular dichroism spectrum. A specific recognition protocol is demonstrated by biotinated YVO4:Eu NPs in quantitative fluoroimmunoassay and microchip assay. Furthermore, the biocompatibility of the Ln NPs, which is an important aspect towards biological application, is demonstrated with the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Cell imaging studies conducted with spectral mapping technique and confocal fluorescent microscopy demonstrate the YVO4:Eu NPs to be a type of competitive luminescent probes for in vitroapplications.
Co-reporter:Jie Shen;Jia-Dan Zhu;Liu-He Wei;Hong-Fang Sun;Chun-Hua Yan
Advanced Functional Materials 2010 Volume 20( Issue 21) pp:
Publication Date(Web):
DOI:10.1002/adfm.201090098
Abstract
Lanthanide nanoparticles (NPs), characterized by their large Stokes’ shifts, narrow emission bands and high photochemical stability, are promising candidates for optical probes in biological research. As a typical red emission material, Eu3+-doped YVO4 is investigated in pursuit of an integral methodology for Ln-based bioprobes. Assisted with phosphino-polyacrylic acid, YVO4:Eu NPs with a luminescent quantum yield of ca. 54% are synthesized via a one-pot hydrothermal reaction. The obtained NPs exhibit good water/buffer stability and feasible biomodification benefiting from the surface carboxylic acid groups. However, having an inorganic core of ca. 20 nm, these NPs do not affect the conformation of surface conjugated proteins (bovine serum albumin), as confirmed with the circular dichroism spectrum. A specific recognition protocol is demonstrated by biotinated YVO4:Eu NPs in quantitative fluoroimmunoassay and microchip assay. Furthermore, the biocompatibility of the Ln NPs, which is an important aspect towards biological application, is demonstrated with the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Cell imaging studies conducted with spectral mapping technique and confocal fluorescent microscopy demonstrate the YVO4:Eu NPs to be a type of competitive luminescent probes for in vitroapplications.
Co-reporter:Jie Shen, Ling-Dong Sun, Ya-Wen Zhang and Chun-Hua Yan
Chemical Communications 2010 vol. 46(Issue 31) pp:5731-5733
Publication Date(Web):28 Jun 2010
DOI:10.1039/C0CC00814A
A crosslinker anchoring process was developed to synthesize Fe3O4/NaYF4:Yb,Er hetero-nanoparticles (NPs) with dual properties of superparamagnetism and upconversion (UC) emission. After ligand ozonolysis treatment, these NPs could be well dispersed in water.
Co-reporter:Wei Feng, Ling-Dong Sun and Chun-Hua Yan
Chemical Communications 2009 (Issue 29) pp:4393-4395
Publication Date(Web):11 Jun 2009
DOI:10.1039/B909164E
Enhanced upconversion emission of NaYF4:Yb,Er nanocrystals with Ag nanowires was observed; the enhancement factor of red emission is larger than that of green emission, and it can be further increased with Ag islands composed of larger Ag particles.
Co-reporter:Shu-Zhuo Zhang, Ling-Dong Sun, He Tian, Ying Liu, Jian-Fang Wang and Chun-Hua Yan
Chemical Communications 2009 (Issue 18) pp:2547-2549
Publication Date(Web):16 Mar 2009
DOI:10.1039/B823453A
Upon the tunable surface plasmon band of the pH-induced reversible assembly of gold nanoparticles mediated by cysteine, the manipulation of green and red upconversion emission, and the switching of the red emission of the NaYF4:Yb,Er nanoparticles have been achieved in a facile and reproducible way.
Co-reporter:Jian-Qin Gu Dr., Dr.;Zheng-Guang Yan Dr. ;Chun-Hua Yan Dr.
Chemistry – An Asian Journal 2008 Volume 3( Issue 10) pp:
Publication Date(Web):
DOI:10.1002/asia.200890029
Co-reporter:Jian-Qin Gu Dr., Dr.;Zheng-Guang Yan Dr. ;Chun-Hua Yan Dr.
Chemistry – An Asian Journal 2008 Volume 3( Issue 10) pp:1857-1864
Publication Date(Web):
DOI:10.1002/asia.200800230
Abstract
This work demonstrates luminescence resonance energy transfer (LRET) sensors based on lanthanide-doped nanoparticles as donors (D) and gold nanoparticles as acceptors (A), combined through electrostatic interactions between the oppositely charged nanoparticles. Negatively charged lanthanide-doped nanoparticles, YVO4:Eu and LaPO4:Ce,Tb, with high luminescence quantum yield and good water-solubility, are synthesized through a polymer-assisted hydrothermal method. Positively charged polyhedral and spherical gold nanoparticles exhibit surface plasmon resonance (SPR) bands centered at 623 and 535 nm, respectively. These bands overlap well with the emission of the Eu3+ and Tb3+ ions within the lanthanide nanoparticles. Herein, the gold nanoparticles are synthesized through a seed-mediated cetyltrimethylammonium bromide (CTAB)-assisted method. The assemblies of the oppositely charged donors and acceptors are developed into LRET-based sensors exhibiting a donor quenching efficiency close to 100 %.
Co-reporter:Chun-Jiang Jia Dr.;Zheng-Guang Yan;Li-Ping You ;Feng Luo;Xiao-Dong Han Dr.;Yu-Cheng Pang;Ze Zhang Dr.;Chun-Hua Yan Dr.
Angewandte Chemie 2005 Volume 117(Issue 28) pp:
Publication Date(Web):15 JUN 2005
DOI:10.1002/ange.200463038
Phosphat-Ionen sind wesentlich: Dies gilt nicht nur für die Bildung der spindelförmigen Vorstufen der einkristallinen Hämatitnanoröhren, die mit einer einfachen Hydrothermalmethode hergestellt wurden, sondern auch für die Adsorptions- und Koordinationseffekte. Der Mechanismus der Röhrenbildung wurde aus Elektronenmikroskopie-Beobachtungen abgeleitet – als ein koordinationsgestützter Auflösungsprozess (siehe Bild).
Co-reporter:Chun-Jiang Jia Dr.;Zheng-Guang Yan;Li-Ping You ;Feng Luo;Xiao-Dong Han Dr.;Yu-Cheng Pang;Ze Zhang Dr.;Chun-Hua Yan Dr.
Angewandte Chemie International Edition 2005 Volume 44(Issue 28) pp:
Publication Date(Web):15 JUN 2005
DOI:10.1002/anie.200463038
Phosphate ions play a crucial role not only for the formation of the spindlelike precursors of the single-crystalline hematite nanotubes that were synthesized by a facile hydrothermal method. They are also important for the adsorption and coordination effects. The mechanism of tube formation was deduced through EM observations as a coordination-assisted dissolution process (see picture).
Co-reporter:Ge ZHANG, Hao DONG, Di WANG, Lingdong SUN, Chunhua YAN
Journal of Rare Earths (January 2017) Volume 35(Issue 1) pp:
Publication Date(Web):1 January 2017
DOI:10.1016/S1002-0721(16)60165-5
The past few years witnessed extensive emergence of short-wavelength upconversion (UC) emission stimulated photoactivation studies. However, low efficiency of multi-photon process greatly limits further applications. Here, ultraviolet (UV) upconversion emissions originated from multi-photon process of Tm3+ were studied with Nd3+-sensitized NaGdF4:Yb, Tm@NaYF4:Nd, Yb core/shell nanoparticles. Crucial factors, including the contents of sensitizers Nd3+, Yb3+ and activator Tm3+, as well as the excitation power density were investigated based on the UV emission. Spectral results showed that high contents of Nd3+ in shell region up to 50% (molar fraction hereafter) and Yb3+ of 10% were essential to mediate the energy transfer via the core/shell interface and facilitate multi-photon UV emissions. Compared with segregated activator and sensitizer, a core/shell strategy with isolated Nd3+ in the shell was important for higher UV emission. Although the upconverting process was initiated with Nd3+→Yb3+, the short-wavelength emissions were intrinsically coming from four- and five-photon process. The optimized nanoparticles were found to be able to manipulate the configuration transition of azobenzene molecules, and it could be promising for near infrared (NIR) triggered optical switches applications.Ultraviolet (UV) upconversion emissions originated from multi-photon process of Tm3+ were studied with Nd3+-sensitized nanoparticles. Coexistence of Nd3+ and Yb3+ is essential to mediate the energy transfer via the core/shell interface. Although the upconverting process is initiated with Nd3+→Yb3+, the short-wavelength emissions are intrinsically coming from four- and five-photon processDownload high-res image (131KB)Download full-size image
Co-reporter:Feng Wang ; Chuanhao Li ; Ling-Dong Sun ; Haoshuai Wu ; Tian Ming ; Jianfang Wang ; Jimmy C. Yu ;Chun-Hua Yan
Journal of the American Chemical Society () pp:
Publication Date(Web):December 21, 2010
DOI:10.1021/ja1095733
The development of high-performance nanocatalysts relies essentially on the generation of stable and active surface sites at the atomic scale through synthetic control of the size, shape, and chemical composition of nanoscale metals and metal oxides. One promising route is to induce the exposure of catalytically active high-index facets of nanostructures through shape-controlled syntheses. We have designed and prepared two types of Pd nanoshells that are enclosed by high-index {730} and {221} facets through heteroepitaxial growth on high-index-faceted Au nanocrystals. The turnover numbers per surface atom of the high-index-faceted Pd nanoshells have been found to be 3−7 times those of Pd and Au−Pd core−shell nanocubes that possess only {100} facets in catalyzing the Suzuki coupling reaction. These results open up a potential for the development of inexpensive and highly active metal nanocatalysts.
Co-reporter:Shu-Zhuo Zhang, Ling-Dong Sun, He Tian, Ying Liu, Jian-Fang Wang and Chun-Hua Yan
Chemical Communications 2009(Issue 18) pp:NaN2549-2549
Publication Date(Web):2009/03/16
DOI:10.1039/B823453A
Upon the tunable surface plasmon band of the pH-induced reversible assembly of gold nanoparticles mediated by cysteine, the manipulation of green and red upconversion emission, and the switching of the red emission of the NaYF4:Yb,Er nanoparticles have been achieved in a facile and reproducible way.
Co-reporter:Wei Feng, Ling-Dong Sun and Chun-Hua Yan
Chemical Communications 2009(Issue 29) pp:NaN4395-4395
Publication Date(Web):2009/06/11
DOI:10.1039/B909164E
Enhanced upconversion emission of NaYF4:Yb,Er nanocrystals with Ag nanowires was observed; the enhancement factor of red emission is larger than that of green emission, and it can be further increased with Ag islands composed of larger Ag particles.
Co-reporter:Hao Dong, Ling-Dong Sun, Ye-Fu Wang, Jia-Wen Xiao, Datao Tu, Xueyuan Chen and Chun-Hua Yan
Journal of Materials Chemistry A 2016 - vol. 4(Issue 19) pp:NaN4192-4192
Publication Date(Web):2016/03/31
DOI:10.1039/C6TC00413J
Exploring novel lanthanide-activated upconversion nanoparticles with distinctive spectral fingerprints and emission lifetimes has long been a great concern for extended optical applications. Herein, we report the study of photon upconversion emissions in Yb3+–Tb3+ and Yb3+–Eu3+ activated nanoparticles with near-infrared excitation. In these nanoparticles, a high content of Yb3+ is required for the simultaneous excitation of two Yb3+ ions, yielding a Yb3+ dimer with a higher excited energy to upconvert photons onto Tb3+ and Eu3+. The optimum doping concentration of Yb3+ ions for Yb3+–Tb3+ and Yb3+–Eu3+ pairs was determined to be 80% and 60%, respectively, which are much higher than that of Yb3+–Er3+/Tm3+ pairs. Notably, the upconversion emission lifetime of the as-prepared nanoparticles was prolonged to 2.3 ms (Tb3+) and 4.0 ms (Eu3+), respectively. Through the epitaxial growth of a Nd3+ doped shell layer, the upconversion emissions of Tb3+ and Eu3+ were intensified 25-fold. At the same time, an extra excitation band in the shorter near-infrared region from Nd3+ at 808 nm was achieved. Moreover, the emissions of Tm3+ were employed to compensate for those of Tb3+ and Eu3+ for multicolor emissions. These results highlight the upconversion emissions of Tb3+ and Eu3+ for potential multicolor imaging and multiplexed detection applications.
Co-reporter:Hao Dong, Ling-Dong Sun and Chun-Hua Yan
Chemical Society Reviews 2015 - vol. 44(Issue 6) pp:NaN1634-1634
Publication Date(Web):2014/09/22
DOI:10.1039/C4CS00188E
Lanthanide pairs, which can upconvert low energy photons into higher energy photons, are promising for efficient upconversion emission. A typical system with Yb3+ as a sensitizer can convert short NIR into visible/ultraviolet light via energy transfer between lanthanide ions. Such upconverting nanocrystals doped with lanthanide ions have found significant potential in bioimaging, photochemical reactions and energy conversion. This review presents a fundamental understanding of energy transfer in lanthanide-supported photon upconversion. We introduce the emerging progress in excitation selection based on the energy transfer within lanthanide ions or activation from antennae, with an outlook in the development and applications of the lanthanide upconversion emissions.
Co-reporter:Jie Shen, Ling-Dong Sun, Ya-Wen Zhang and Chun-Hua Yan
Chemical Communications 2010 - vol. 46(Issue 31) pp:NaN5733-5733
Publication Date(Web):2010/06/28
DOI:10.1039/C0CC00814A
A crosslinker anchoring process was developed to synthesize Fe3O4/NaYF4:Yb,Er hetero-nanoparticles (NPs) with dual properties of superparamagnetism and upconversion (UC) emission. After ligand ozonolysis treatment, these NPs could be well dispersed in water.
Co-reporter:Tao Zheng, Ling-Dong Sun, Jia-Cai Zhou, Wei Feng, Chao Zhang and Chun-Hua Yan
Chemical Communications 2013 - vol. 49(Issue 51) pp:NaN5801-5801
Publication Date(Web):2013/02/07
DOI:10.1039/C3CC39108F
Monodispersed nanocrystals (NCs) can form ordered and functional binary superlattices. A variety of functional binary nanocrystal superlattices (BNSLs) and bilayer assemblies based on lanthanide-doped NaREF4 (RE = Y, Gd) were constructed with different assembly methods. These assemblies are attractive for applications in photonics as they display multicolor upconversion (UC) emissions.
