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991.
Yang Zhao Yue‐Jiao Zhang Jin‐Hui Meng Shu Chen Rajapandiyan Panneerselvam Chao‐Yu Li Sain Bux Jamali Xia Li Zhi‐Lin Yang Jian‐Feng Li Zhong‐Qun Tian 《Journal of Raman spectroscopy : JRS》2016,47(6):662-667
Silver nanoparticles (Ag NPs) enjoy a reputation as an ultrasensitive substrate for surface‐enhanced Raman spectroscopy (SERS). However, large‐scale synthesis of Ag NPs in a controlled manner is a challenging task for a long period of time. Here, we reported a simple seed‐mediated method to synthesize Ag NPs with controllable sizes from 50 to 300 nm, which were characterized by scanning electron microscopy (SEM) and UV–Vis spectroscopy. SERS spectra of Rhodamine 6G (R6G) from the as‐prepared Ag NPs substrates indicate that the enhancement capability of Ag NPs varies with different excitation wavelengths. The Ag NPs with average sizes of ~150, ~175, and ~225 nm show the highest SERS activities for 532, 633, and 785‐nm excitation, respectively. Significantly, 150‐nm Ag NPs exhibit an enhancement factor exceeding 108 for pyridine (Py) molecules in electrochemical SERS (EC‐SERS) measurements. Furthermore, finite‐difference time‐domain (FDTD) calculation is employed to explain the size‐dependent SERS activity. Finally, the potential of the as‐prepared SERS substrates is demonstrated with the detection of malachite green. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
992.
A Nanoscale Multiresponsive Luminescent Sensor Based on a Terbium(III) Metal–Organic Framework 下载免费PDF全文
Dr. Song Dang Dr. Ting Wang Dr. Feiyan Yi Dr. Qinghui Liu Dr. Weiting Yang Prof. Zhong‐Ming Sun 《化学:亚洲杂志》2015,10(8):1703-1709
A nanoscale terbium‐containing metal–organic framework ( nTbL ), with a layer‐like structure and [H2NMe2]+ cations located in the framework channels, was synthesized under hydrothermal conditions. The structure of the as‐prepared sample was systematically confirmed by powder XRD and elemental analysis; the morphology was characterized by field‐emission SEM and TEM. The photoluminescence studies revealed that rod‐like nTbL exhibited bright‐green emission, corresponding to 5D4→7FJ (J=6–3) transitions of the Tb3+ ion under excitation. Further sensing measurements revealed that as‐prepared nTbL could be utilized as a multiresponsive luminescent sensor, which showed significant and exclusive detection ability for Fe3+ ions and phenylmethanol. These results highlight the practical applications of lanthanide‐containing metal–organic frameworks as fluorescent probes. 相似文献
993.
Zhuliang Zhong Donghui Ma Gaoyuan Zhao Huilin Li Dengyu Xu Dr. Xingang Xie Prof. Dr. Xuegong She 《化学:亚洲杂志》2015,10(12):2599-2603
The first asymmetric total synthesis of kravanhin B has been accomplished with a linear reaction sequence of 13 steps starting from (R)‐(?)‐carvone. The synthesis features an intramolecular aldol cyclization to construct the desired cis‐fused decalin skeleton and an acid‐catalyzed dehydration and olefin isomerization to install the γ‐butenolide ring. 相似文献
994.
Aggregation-induced emission (AIE) is a unique and significant photophysical phenomenon that differs greatly from the commonly acknowledged aggregation-caused emission quenching observed for many π-conjugated planar chromophores. The mechanistic decipherment of the AIE phenomenon is of high importance for the advance of new AIE systems and exploitation of their potential applications. Propeller-like 2,3,4,5-tetraphenylsiloles are archetypal AIE-active luminogens, and have been adopted as a core part in the design of numerous luminescent materials with diverse functionalities. In this review article, we elucidate the impacts of substituents on the AIE activity and shed light on the structure–property relationship of siloles, with the aim of promoting the judicious design of AIE-active functional materials in the future. Recent representative advances of new silole-based functional materials and their potential applications are reviewed as well. 相似文献
995.
Ming Chen Lingzhi Li Han Nie Jiaqi Tong Lulin Yan Bin Xu Jing Zhi Sun Wenjing Tian Zujin Zhao Anjun Qin Ben Zhong Tang 《Chemical science》2015,6(3):1932-1937
Research on aggregation-induced emission (AIE) has been a hot topic. Due to enthusiastic efforts by many researchers, hundreds of AIE luminogens (AIEgens) have been generated which were mainly based on archetypal silole, tetraphenylethene, distyrylanthracene, triphenylethene, and tetraphenyl-1,4-butadiene, etc. To enlarge the family of AIEgens and to enrich their functions, new AIEgens are in high demand. In this work, we report a new kind of AIEgen based on tetraphenylpyrazine (TPP), which could be readily prepared under mild reaction conditions. Furthermore, we show that the TPP derivatives possess a good thermal stability and their emission could be fine-tuned by varying the substituents on their phenyl rings. It is anticipated that TPP derivatives could serve as a new type of widely utilized AIEgen, based on their facile preparation, good thermo-, photo- and chemostabilities, and efficient emission. 相似文献
996.
Synthesis of Bi2WO6/Bi2O3 Composite with Enhanced Photocatalytic Activity by a Facile One‐step Hydrothermal Synthesis Route 下载免费PDF全文
Tianye Wang Fengjun Zhang Guosheng Xiao Shuang Zhong Cong Lu 《Photochemistry and photobiology》2015,91(2):291-297
In this study, the characterization and photocatalytic activity of Bi2WO6/Bi2O3 under visible‐light irradiation was investigated in detail. The results suggested that Bi2WO6/Bi2O3 can be synthesized by a facile one‐pot hydrothermal route using a super big 200 mL Teflon‐lined autoclave with optimal sodium oleate/Bi molar ratio of 1.25. Through the characterization of Bi2WO6/Bi2O3 by X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy, Fourier transform infrared, UV‐vis diffuse reflectance spectra and Photoluminescence spectra, it was found that the as‐prepared composite possessed smaller crystallite size and higher visible‐light responsive than the pure Bi2WO6. Moreover, it was expected that the as‐prepared composites exhibited enhanced photocatalytic activity for the degradation of Rhodamine B under visible‐light irradiation, which could be ascribed to their improved light absorption property and the reduced recombination of the photogenerated electrons and holes during the photocatalytic reaction. In general, this study could provide a principle method to synthesize Bi2WO6/Bi2O3 with enhanced photocatalytic activity by one‐step hydrothermal synthesis route for environmental purification. 相似文献
997.
UVR8 is the only known plant photoreceptor that mediates light responses to UV‐B (280–315 nm) of the solar spectrum. UVR8 perceives a UV‐B signal via light‐induced dimer dissociation, which triggers a wide range of cellular responses involved in photomorphogenesis and photoprotection. Two recent crystal structures of Arabidopsis thaliana UVR8 (AtUVR8) have revealed unusual clustering of UV‐B‐absorbing Trp pigments at the dimer interface and provided a structural framework for further mechanistic investigation. This review summarizes recent advances in spectroscopic, computational and crystallographic studies on UVR8 that are directed toward full understanding of UV‐B perception at the molecular level. 相似文献
998.
Susceptibility of Ureaplasma urealyticum to Methylene Blue‐Mediated Photodynamic Antimicrobial Chemotherapy: An in vitro Study 下载免费PDF全文
Tinglu Ye Bancheng Chen Bo Yu Qili Zhong Guoxin Huang Xiaoping Hu Wei Zhang 《Photochemistry and photobiology》2015,91(4):917-922
The aim of this study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL?1) for 20 or 60 min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100 mW cm?2 for 8, 17, 34 or 68 min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections. 相似文献
999.
The Convenient Synthesis of 11‐Methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione Derivatives 下载免费PDF全文
Guang‐Fan Han Li‐Jun Zhao Li‐Zhuang Chen Jia‐Wei Du Zhong‐Xia Wang 《Journal of heterocyclic chemistry》2015,52(4):1219-1225
The 2‐arylidene‐3‐oxobutanenitrile derivatives 2 were prepared by the Knoevenagel condensation between aldehydes and 3‐oxobutanenitrile 1 , which was obtained by acid hydrolysis of β‐aminocrotononitrile. 3‐Acetyl‐2‐amino‐4H‐chromen‐5(6H)‐one derivatives 3 were synthesized by reaction of 2‐arylidene‐3‐oxobutanenitrile 2 and 5‐substituted‐1,3‐cyclohexanedione in ethylene glycol. The 11‐methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione derivatives 4 were obtained by Friedländer reaction of compounds 3 with 5‐substituted‐1,3‐cyclohexanedione, using p‐toluenesulfonic acid monohydrate as catalyst. The structures of all novel compounds were characterized by elemental analysis, IR, MS, and 1H NMR spectra. The crystal and molecular structure of compound 4f has been determined by single crystal XRD analysis. 相似文献
1000.
Zhixiong Zhong Gongke Li Zhibin Luo Zhe Liu Yijuan Shao Wanwen He Jianchao Deng Xingling Luo 《Analytica chimica acta》2015
A carboxylated graphene oxide/polyvinyl chloride (CGO/PVC) material was prepared as a sorbent for the selective extraction of sulphonamides from complex sample. After being dispersed in buffer solution, sample was transferred into the prefabricated solid-phase extraction (SPE) column, which integrated extraction and cleanup into one single-step. A multi-response optimization based on the Box-Behnken design was used to optimize factors affecting extraction efficiency. Compared with the commonly commercial sorbents including MCX, WCX and C18, CGO/PVC hybrid material had higher extraction selectivity and capacity to sulphonamides. The limits of detection and quantification for seven target compounds were in the range of 3.4–7.1 μg/L and 11.4–23.7 μg/L, respectively. The self-assembly SPE cartridge was successfully used to enrich seven analytes in anti-acne cosmetics prior to ion chromatography detection with good recoveries of 87.8–102.0% and relative standard deviations of 1.2–6.4%, implying that this method was suitable for routine analysis of cosmetics. 相似文献