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81.
Graphene oxide (GO) has been considered as a promising stationary phase for chromatographic separation. However, the very strong adsorption of the analytes on the GO surface lead to the severe peak tailing, which in turn resulting in decreased separation performance. In this work, GO and silica nanoparticles hybrid nanostructures (GO/SiO2 NPs@column) were coated onto the capillary inner wall by passing the mixture of GO and silica sol through the capillary column. The successful of coating of GO/SiO2 NPs onto the capillary wall was confirmed by SEM and electroosmotic flow mobilities test. By partially covering the GO surface with silica nanoparticles, the peak tailing was decreased greatly while the unique high shape selectivity arises from the surface of remained GO was kept. Consequently, compared with the column modified with GO (GO@column), the column modified with GO and silica nanoparticles through layer‐by‐layer method (GO‐SiO2 NPs@column), or the column modified with silica nanoparticles (SiO2 NPs@column), GO/SiO2 NPs@column possessed highest resolutions. The GO/SiO2 NPs@column was applied to separate egg white and both acidic and basic proteins as well as three glycoisoforms of ovalbumin were separated in a single run within 36 min. The intra‐day, inter‐day, and column‐to‐column reproducibilities were evaluated by calculating the RSDs of the retention of naphthalene and biphenyl in open‐tubular capillary electrochromatography. The RSD values were found to be less than 7.1%. 相似文献
82.
Jin?ZhouEmail author Hui?Zhou Jinbao?Tang Shue?Deng Fang?Yan Wenjing?Li Meihua?Qu 《Mikrochimica acta》2017,184(2):343-368
Carbon dots (CDs) possess superior fluorescent properties in that they do not blink, are biocompatible, chemically inert, have small size and well tunable photoluminescence (PL), can be easily functionalized with biomolecules, and can be multi-photon excited to give up-converted PL. This review (with 141 refs.) summarizes recent progress in the field of imaging using carbon dots doped with heteroatoms (X-CDs). Following an introduction, we discuss top-down and bottom-up strategies for synthesis and methods for surface modification. We also compare the differences in synthesis for undoped CDs and X-CDs. Specifically, CDs doped with heteroelemets nitrogen, phosphorus, sulfur, selenium, boron and silicium are treated. We then discuss method for determination of the properties (particle size, ZP), how doping affects fluorescence (spectra, quantum yields, decay times), and how dopants affect upconversion (UC, anti-Stokes luminescence). We finally review the progress made in fluorescent imaging of cells tissue, and other biomatter. This review also gives new hints on how to use synthetic methods for tuning the structure of X-CDs, how doping affects properties, and how to achieve new bioimaging applications. 相似文献
83.
A new dual chemosensor (TTF-PBA) for Fe3+ and Cu2+ in different signal pathways was designed and synthesized. The absorption spectrum, fluorescence spectrum and cyclic voltammograms changed in the presence of Cu2+ and Fe3+. The optical color changed within 5 s from yellow to orange upon the addition of Cu2+, and it changed to dark yellow when Fe3+ existed. The cyclic voltammogram of Cu2+/TTF-PBA changed from Eox = 0.50 V, Ered = 0.32 V to Eox = 0.64 V, Ered = 0.80 V (vs Ag/AgCl) upon the addition of 2.0 equiv. Cu2+. As for Fe3+/TTF-PBA, its oxidation wave disappeared, and its reduction wave appeared at Ered = ?0.59 V (vs Ag/AgCl) upon the addition of 4.0 equv. Fe3+. The sensor displayed high selectivity for Cu2+ and Fe3+ over other ions including Pb2+, Zn2+, Ni2+, Ag+, Cr3+, Mn2+, Al3+, Co2+, Pd2+, Hg2+, Fe2+, Cd2+, Ce3+, Bi3+ and Au3+, the detection limits for Cu2+ and Fe3+ ion reached as low as 5.33 × 10?7 mol/L and 5.34 × 10?7 mol/L, respectively. Furthermore, when Fe3+ existed, Cu2+ can be detected sequentially by the sensor through the absorption spectrum and the color change observed by naked-eyes. 相似文献
84.
Ge Liu Jie Shao Youjun Gao Zheng Chen Qunting Qu 《Journal of Solid State Electrochemistry》2017,21(9):2593-2600
Sandwich-structured C@Fe3O4@C hybrids with Fe3O4 nanoparticles sandwiched between two conductive carbon layers have attracted more and more attention owing to enhanced synergistic effects for lithium-ion storage. In this work, an environment-friendly procedure is developed for the fabrication of sandwich-like C@Fe3O4@C dodecahedrons. Zeolitic imidazolate framework (ZIF-8)-derived carbon dodecahedrons (ZIF-C) are used as the carbon matrix, on which iron precursors are homogeneously grown with the assistance of a polyelectrolyte layer. The subsequent polydopamine (PDA) coating and calcination give rise to the formation of sandwiched ZIF-C@Fe3O4@C. When being evaluated as the anode material for lithium-ion batteries, the obtained hybrid manifests a high reversible capacity (1194 mAh g?1 at 0.05 A g?1), good high-rate behavior (796 mAh g?1 at 10 A g?1), and negligible capacity loss after 120 cycles. 相似文献
85.
86.
Yanyan Huang Dr. Youhui Lin Xiang Ran Prof. Dr. Jinsong Ren Prof. Dr. Xiaogang Qu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(16):5705-5711
Herein, to mimic complex natural system, polyelectrolyte multilayer (PEM)‐coated mesoporous silica nanoreactors were used to compartmentalize two different artificial enzymes. PEMs coated on the surface of mesoporous silica could serve as a permeable membrane to control the flow of molecules. When assembling hemin on the surface of mesoporous silica, the hemin‐based mesoporous silica system possessed remarkable peroxidase‐like activity, especially at physiological pH, and could be recycled more easily than traditional graphene–hemin nanocompounds. The hope is that these new findings may pave the way for exploring novel nanoreactors to achieve compartmentalization of nanozymes and applying artificial cascade catalytic systems to mimic cell organelles or important biochemical transformations 相似文献
87.
Tobias Heurich Dr. Zheng‐Wang Qu Dr. Senada Nožinović Dr. Gregor Schnakenburg Dr. Hideto Matsuoka Prof. Dr. Stefan Grimme Prof. Dr. Olav Schiemann Prof. Dr. Rainer Streubel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(29):10102-10110
Low‐temperature generation of P‐nitroxyl phosphane 2 (Ph2POTEMP), which was obtained by the reaction of Ph2PH ( 1 ) with two equivalents of TEMPO, is presented. Upon warming, phosphane 2 decomposed to give P‐nitroxyl phosphane P‐oxide 3 (Ph2P(O)OTEMP) as one of the final products. This facile synthetic protocol also enabled access to P‐sulfide and P‐borane derivatives 7 and 13 , respectively, by using Ph2P(S)H ( 6 ) or Ph2P(BH3)H ( 11 ) and TEMPO. Phosphane sulfide 7 revealed a rearrangement to phosphane oxide 8 (Ph2P(O)STEMP) in CDCl3 at ambient temperature, whereas in THF, thermal decomposition of sulfide 7 yielded salt 10 ([TEMP‐H2][Ph2P(S)O]). As well as EPR and detailed NMR kinetic studies, indepth theoretical studies provided an insight into the reaction pathways and spin‐density distributions of the reactive intermediates. 相似文献
88.
89.