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891.
A two-photon excited luminescence of water-soluble rhodamine-platinum(II) complex: fluorescent probe specific for Hg2+ detection in live cell 总被引:1,自引:0,他引:1
The first example of cyclometalated platinum(II)-containing rhodamine probe (1) with two-photon induced luminescent properties was synthesized and investigated for mercury detection. A highly selective color change of 1, from light yellow to pink, is observed only in the presence of Hg2+ due to the formation of 1,3,4-oxadiazole ring in 2. This selectivity of Hg2+ with color changes can be observed easily by the naked-eye. Meanwhile, a remarkable turn-on and selective 20-fold fluorescent enhancement of 1 upon binding with Hg2+ over the other tested metal ions was observed. The water-soluble probe 1 was successfully applied in the visualizing of the site of Hg2+ accumulation as well as estimating of trace amounts of mercury ions in live HeLa cells by two-photon microscopy. 相似文献
892.
In this study we firstly report a new electrolytic cold vapor generation system for mercury determination on Pt/Ti cathode in the presence of organic acid catholyte. Comparing with the traditional inorganic acid, formic acid increased the signal intensity of Hg vapor from electrolytic generation on Pt cathode and reduced the impact of cathode erosion on the stability of signal intensity. Moreover, formic acid has better interference tolerance. The introduction location for carrier gas is probably the most important factor that influences the signal intensity of Hg from electrolytic vapor generation. The effects of the electrolytic conditions and interference ions on the ECVG have been studied. Under the optimized conditions, the detection limit (3σ) of Hg (II) in aqueous solutions is 1.4 ng L−1; a relative standard deviation of 2.3% for 1 μg L−1 Hg was obtained. The accuracy of this method was verified by the determination of mercury in the certified reference materials. This system has been applied satisfactorily to the determination of Hg in Traditional Chinese Medicines samples. 相似文献
893.
A nonenzymatic amperometric sensor for sensitive and selective detection of glucose has been constructed by using highly dispersed Pt nanoparticles supported onto mesoporous carbons (MCs). The Pt nanoparticles/mesoporous carbons (Pt/MCs) composites modified electrode displayed high electrocatalytic activity towards the oxidation of glucose. At an applied potential of 0.1 V, the Pt/MCs electrode has a linear dependence (R=0.996) in the glucose concentration up to 7.5 mM with a sensitivity of 8.52 mA M?1 cm?2. The Pt/MCs electrode has also shown highly resistant toward poisoning by chloride ions and without interference from the oxidation of common interfering species. 相似文献
894.
Three new guaipyridine sesquiterpene alkaloids, rupestine A, B, C ( 1 – 3 , resp.), and the new nor‐sesquiterpne alkaloid rupestine D ( 4 ) were obtained from the flowers of Artemisia rupestris L. Their structures were elucidated on the basis of sepectroscopic data and by comparison with those of the related compounds reported in the literature. In addition, the absolute configurations of 2 and 4 were determined by single‐crystal X‐ray diffraction analyses. 相似文献
895.
896.
Water-soluble CdTe quantum-dots (QDs) of different sizes and capped with mercaptosuccinic acid were prepared by the microwave irradiation method. The QDs can significantly enhance the chemiluminescence (CL) of the pyrogallol-H2O2 system. Those with a diameter of 3.8 nm produce the most intense CL. UV-vis, photoluminescence, and CL spectra were acquired in order to explore the effect. The results showed that the chromium(III) ion in the concentration range from 20 pM to 30 µM enhances CL, and this is exploited for its trace determination.The limit of detection (3σ) is 6 pM, with a relative standard deviation (n?=?11) of 1.7%. A continuous flow injection CL method was developed and applied to the determination of chromium(III) in tap water and lake water samples with satisfactory results. 相似文献
897.
898.
Yan Cai Hong Xu Yongmei Xia Yafen Su Yun Fang 《Applied biochemistry and biotechnology》2010,162(4):1147-1152
Soybean lipoxygenase (LOX) contains endogenous iron (II) at the active site, which is important for the enzyme activity. The activity of LOX can be accelerated by some exogenous metal ions including Cu2+. However, the mechanism of the activity improvement caused by exogenous metal ions remains unclear, not only for LOX but for most other metalloenzymes. Meanwhile, the possibility that exogenous metal ions can displace endogenous iron (II) is still in discussion for a lack of a direct and quantitative proof. In this paper, a quantitative proof of replacing iron (II) inside LOX by exogenous Cu2+ was provided, simply using UV-Vis spectrometry with two indicators p-carboxylantipyrylazo and 9-(4-carboxyphenyl)-2,3,7-trihydroxyl-6-fluorine. A 0.56 μM free iron (II) was observed in the bulk solution after incubating 9.45 μM Cu2+ with 16.10 μM LOX at 20°C for 5 min, which is in coincidence with the decrement of Cu2+ in the bulk solution (0.53 μM), implying that iron (II) was replaced by Cu2+. 相似文献
899.
A high-performance gas–liquid transmission device (HPTD) was described in this paper. To investigate the HPTD mass transfer
characteristics, the overall volumetric mass transfer coefficients,
K\textLa,\textCO2 \textA K_{{\text{La}},{\text{CO}}_2 }^{\text{A}} for the absorption of gaseous CO2 and
K\textLa,\textO2 \textD K_{{\text{La}},{\text{O}}_2 }^{\text{D}} for the desorption of dissolved O2 were determined, respectively, by titration and dissolved oxygen electrode. The mass transfer capability of carbon dioxide
was compared with that of dissolved oxygen in the device, and the operating conditions were optimized to suit for the large-scale
enclosed micro-algae cultivation. Based on the effectiveness evaluation of the HPTD applied in one enclosed flat plate Spirulina culture system, it was confirmed that the HPTD can satisfy the demand of the enclosed system for carbon supplement and excessive
oxygen removal. 相似文献
900.
Jing-An Zhang Mei Pan Rui Yang Zhi-Gang She Wolfgang Kaim Zhi-Jin Fan Cheng-Yong Su 《Polyhedron》2010
The semirigid tridentate 8-(2-pyridinylmethylthio)quinoline ligand (Q1) is shown to form the structurally characterized transition metal complexes [Cu(Q1)Cl2] (1), [Co(Q1)(NO3)2] (2), [Cd(Q1)(NO3)2] (3), [Cd(Q1)I2] (4). [Cu(Q1)2](BF4)2·(H2O)2 (5), [Cu(Q1)2](ClO4)2·(CH3COCH3)2 (6), [Zn(Q1)2](ClO4)2(H2O)2 (7), [Cd2(Q1)2Br4] (8), [Ag2(Q1)2(ClO4)2] (9), and [Ag2(Q1)2(NO3)2] (10). Four types of structures have been observed: ML-type in complexes 1–4, in which the anions Cl−, NO3− or I− also participate in the coordination; ML2− type in complexes 5–7 without direct coordination of the anions BF4− or ClO4− and with more (Cu2+) or less (Zn2+) distorted bis-fac coordinated Q1; M2L2-type in complex 8, in which two Br− ions act as bridges between two metal ions; and M2(μ-L)2-type in complexes 9 and 10, in which the ligand bridges two anion binding and Ag–Ag bonded ions. Depending on electron configuration and size, different coordination patterns are observed with the bonds from the metal ions to Npyridyl longer or shorter than those to Nquinoline. Typically Q1 acts as a facially coordinating tridentate chelate ligand except for the compounds 9 and 10 with low-coordinate silver(I). Except for 6 and 8, the complexes exhibit distinct constraining effects against both G(+) and G(-) bacteria. Complexes 1, 3, 4, 5, 7 have considerable antifungal activities and complexes 1, 5, 7, and 10 show selective effects to restrain certain botanic bacteria. Electrochemical studies show quasi-reversible reduction behavior for the copper(II) complexes 1, 5 and 6. 相似文献