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941.
The title complex l-[CuⅡ4(Hvap)2(vap)2(MeOH)2](CIO4)2 1 has been synthesized and characterized by EA. IR,TGA,solid-state CD spectra and X-ray single-crystal analyses(l-H2vap’.a Schiff base ligand derived from the condensation of o-vanillin and l-2-amino-3-phenyl-l-propanol).Complex 1 crystallizes in monoclinic system,chiral space group P21 with a =10.4257(18).b = 21.695(4),c = 15.721(3)A,β= 94.443(3).V= 3545.1(11) 3,Z=2,Cu4C70H78N4O22Cl2.Mr= 1652.42,Dc= 1.548 g/cm3, F(000)= 1704 andμ(MoKα) = 1.338 mm-1.The final R = 0.0682 and wR = 0.1420 for 6170 observed reflections with I > 2σ(I) and R = 0.1775 and wR = 0.1830 for all data.The structure of complex 1 contains a boat-shaped(Cu4O4} motif.The solid-state CD spectra confirm the chiral nature of complex 1. 相似文献
942.
A novel supramolecular graft copolymer(SGP) composed of viologen-containing copolymer(P(DMA-co-diEV)) as the main chain and Np ended PNIPAM(Np-PN1PAm) as the grafts is prepared(DMA:N,N- dimethylacryamide,diEV:ethylviologen dimer,Np:naphthalene,PNIPAM:poly(N-isopropylacrylamide)). The grafting is based on the triple complexation among a host of cucurbit[8]uril(CB[8])and two guests of diEV and Np,which is characterized by UV-vis spectra and ITC.Temperature sensitive property of PNIPAm moiety allows SGP to self-assemble into non-covalently connected micelle(NCCM) at high temperature. The micelles are sensitive to reducing agents,for example Na2S2O3,which breaks the current inclusion complex pair and induces aggregation. 相似文献
943.
通过高效的反应精确合成功能分子已成为现代化学发展的趋势之一。基于呋喃/马来酰亚胺(MI)之间的Diels-Alder(D-A)反应作为一种高效的和高选择性的点击反应,克服了铜催化的叠氮/炔之间的1,3-偶极环化加成(CuAAC)反应中引起的金属污染等缺点,为生物医药载体、功能性材料的制备提供更可行的途径。同时,呋喃/MI之间的D-A反应具备原料易得、反应条件温和及易发生retro D-A(rD-A)反应等优点,在制备响应性材料领域备受关注。本文综述了近年基于呋喃/MI的可逆D-A反应在响应性聚合物合成、智能材料、生物分子及表面修饰等方面的应用,并展望了D-A反应的发展前景。 相似文献
944.
945.
946.
947.
A modified glassy carbon (GC) electrode was developed for the amperometric detection of biogenic amines, particularly histamine. The electrode was modified with the co‐enzyme pyrroloquinoline quinone (PQQ) by entrapment during electropolymerziation of pyrrole to form polypyrrole (PPy). This method formed a thin film on the electrode surface possessing very good stability with a shelf‐life exceeding one month without loss of signal. Optimal conditions for the PQQ/PPy electrode were determined and a linear response was found for histamine in phosphate buffer (pH 6) at +550 mV from 40 to 170 mg L?1 with a limit of detection (S/N≥3) of 38 mg L?1. The practical linear range offered by this method suggests ideal use for spoilage detection in fermented foods. 相似文献
948.
Hankun Zhou Si Chen Ning Gan Tianhua Li Yuting Cao Qianli Jiang 《Electroanalysis》2013,25(10):2384-2393
A novel sandwich‐type electrochemiluminescence (ECL) immunosensor was developed to enable the sensitive detection of HIV‐1 antibodies. This system incorporated mesoporous silica (mSiO2) complexed with quantum dots (QDs) and nano‐gold particles, which were assembled to enhance signal detection. Magnetic beads were used by immobilizing the secondary anti‐IgG antibody. This was first employed to capture HIV‐1 antibody (Ab) to form a Fe3O4/anti‐IgG/Ab complex. A high loading and signal‐enhanced nanocomposite (hereafter referred to as Au‐mSiO2‐CdTe) was used as a HIV‐1 antigen label. The Au‐mSiO2‐CdTe nanocomposite was conjugated with the Fe3O4/anti‐IgG/Ab complex to form an immunocomplex (hereafter referred to as Fe3O4/anti‐IgG/Ab/HIV‐1/CdTe‐mSiO2‐Au). This complex could be further separated by an external magnetic field to produce ECL signals. Due to the large specific surface area and pore volume of mSiO2, the loading of the CdTe QDs was markedly increased. Thus, the loaded QDs released a powerful chemiluminescent signal with a concordantly increased sensitivity of the immunosensor. The immunosensor was highly sensitive, and displayed a linear range of responses for HIV‐1 antibody across a dilution range of 1 : 1500 through 1 : 50 with the detection limit of 1 : 4500. The immunoassay can be a promising candidate in early diagnosis of HIV infection. 相似文献
949.
Yue-Wei Zhang Hai-Yu Yan Ping Fu Fei Jiang Yao Zhang Wen-Xue Wu Jin-Xiang Li 《Analytical and bioanalytical chemistry》2013,405(16):5549-5555
The recognition of targets such as biomacromolecules, viruses and cells by their aptamers is crucial in aptamer-based biosensor platforms and research into protein function. However, it is difficult to evaluate the binding constant of aptamers and their targets that are hard to purify and quantify, especially when the targets are undefined. Therefore, we aimed to develop a modified capillary electrophoresis based method to determine the dissociation constant of aptamers whose targets are hard to quantify. A protein target, human thrombin, and one of its aptamers were used to validate our modified method. We demonstrated that the result calculated by our method, only depending on the aptamer’s concentrations, was consistent with the classical method, which depended on the concentrations of both the aptamers and the targets. Furthermore, a series of DNA aptamers binding with avian influenza virus H9N2 were confirmed by a four-round selection of capillary electrophoresis–systematic evolution of ligands by exponential enrichment, and we identified the binding constant of these aptamers by directly using the whole virus as the target with the modified method. In conclusion, our modified method was validated to study the interaction between the aptamer and its target, and it may also advance the evaluation of other receptor–ligand interactions. 相似文献
950.
Tingting Wang Zhenghua Liu Jacques Crommen Zhengjin Jiang 《Journal of separation science》2013,36(9-10):1568-1574
In this study, the partial filling technique on both polycationic polymer hexadimethrine bromide (HDB) modified capillary and eCAP neutral capillary were systematically compared in order to enhance the enantioseparation ability of bromobalhimycin as CE additive. The separation conditions, such as pH, the plug length, and the concentration of bromobalhimycin, etc., were optimized in order to obtain satisfactory separations. As expected, for all tested 28 N‐benzoylated amino acids, up to five times higher enantioresolutions were obtained on the eCAP neutral capillary compared to that on the polycationic polymer hexadimethrine bromide modified capillary. Moreover, 26 of 28 tested racemic compounds were almost baseline‐ resolved without observing any interference from the front of the plug of bromobalhimycin. Although the limitation of longer running time on the neutral capillary, it allows the use of higher content of bromobalhimycin in the running buffer without any interference on the detection of analytes when enantioseparations are more difficult to obtain. 相似文献