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71.
《Analytical letters》2012,45(15):3271-3283
ABSTRACT Six kinds of water-soluble porphyrin were examined as a sensitizer (fluorophore) in the bis(2,4,6-trichlorophenyl)oxalate(TCPO)-hydrogen peroxide (H2O2) chemiluminescence(CL) system. Among them, coproporphyrin III showed the highest CL intensity. Moreover, the TCPO-H2O2-coproporphyrin III CL system was separately examined in each micelle solution using a non-ionic surfactant such as Briji 35 and Triton X-100, and an ionic surfactant such as cetyltrimethylammonium chloride(CTAC) and sodium dodecylsulfate. As a result, the CL intensity along with the coexistence of the CTAC micelle increased approximately 36 times compared to that in the absence of surfactant. Based on these findings, the quenching CL determination of copper(II) was established using the complex formation of coproporphyrin III and copper(II) ion. The calibration graph for the concentration of copper(II) was linear in the range of 2×10?8M to 1×10?6M, and the detection limit(3σ) was 1.26×10?8M. Moreover, the relative standard deviation was 2.9%(10 determinations). The proposed method was applied to the determination of copper(II) ion in waste water and satisfactory results were obtained. 相似文献
72.
73.
Junfeng Li Fengyan Song Lu Wang Jieming Jiao Yixiang Cheng Chengjian Zhu 《Macromolecular rapid communications》2012,33(15):1268-1272
A novel polymer P‐1 is prepared by the reaction of the monomer 5,5′‐divinyl‐2,2′‐bipyridine and Salen‐Zn(II) via Heck cross coupling. Interestingly, P‐1 can further incorporate with Eu(TTA)3·2H2O to generate copolymer P‐2 with two different metal centers. P‐2 exhibits exceptional dual emissive properties which can be tuned by excitation wavelength. For example, an orange fluorescence can be obtained when P‐2 is excited at 430 nm, whereas a red emission with a huge Stoke shift of 57 nm is observed when it is excited at 345 nm. The high wavelength emission can be attributed to Eu(III) (5D0→7F2), which is lit by an effective photoinduced energy transfer process between P‐1 and the Eu(TTA)3 complex. The properties of P‐2 have led to a better understanding of the energy transfer process between P‐1 and Eu(TTA)3 moieties. 相似文献
74.
Maria I. N. da Silva Alexandra A. P. Mansur Vanessa Schatkoski Klaus W. H. Krambrock Juan González Herman S. Mansur 《Macromolecular Symposia》2012,319(1):114-120
Summary: In this study it is presented the synthesis and the characterization of Fluorescent-Magnetic Nanostructures based on polymer-quantum dots conjugates. Polyvinyl alcohol (PVA) was used as the capping-ligand for the preparation of CdxMn1-xS semiconductor nanocrystals via aqueous colloidal chemistry. Different substitution ratios of Cd2+ by Mn+2 ions were investigated aiming at the formation of stable nanoparticles with photo-luminescent and semi-magnetic properties. UV-visible spectroscopy (UV-vis), photoluminescence spectroscopy (PL), Electric Paramagnetic Resonance Spectroscopy (EPR), and transmission electron microscopy (TEM) were used to characterize the formation and the relative stability of CdxMn1-xS nanoparticles. The results have showed the influence of the Mn2+partially replacing Cd2+ in the optical behavior of the quantum dots (QDs) produced. In addition, the CdxMn1-xS QDs have evidenced luminescent and semi-magnetic properties. Thus, the biocompatible water-soluble polymer was effective as ligand for synthesizing and stabilizing QDs conjugates with properties allowing them to be potentially applied as imaging and labeling probes in the biomedical field. 相似文献
75.
以聚乙炔、聚芴、聚噻吩、聚苯撑为代表的荧光共轭聚合物,由于具有独特的光学性能、自组装性能和结构与性能的可调控性,可作为优异的光学传感材料。利用其具有较高摩尔消光系数和荧光量子产率的特点,可设计具有较高灵敏度和选择性的传感器,这已成为生物传感领域的研究热点。以荧光共轭聚合物为基础的金属离子检测,最初是以非水溶性的共轭聚合物为主,通过金属离子与聚合物链上特定基团(如吡啶、冠醚)的结合引起的聚合物荧光性质的变化可实现对某些离子的检测。在共轭聚合物主链上引入亲水性侧链,可大大增强共轭聚合物的水溶性,为金属离子的生物传感检测提供了新的思路,例如可引入能与金属离子结合的生物分子(如DNA、糖基等)来设计传感策略,进一步提高检测的特异性和灵敏度。本文综述了近年来以非水溶性和水溶性荧光共轭聚合物为传感材料,对具有重要生物学意义的重金属离子(Hg2+、Pb2+)、过渡金属离子(Cu2+、Eu3+、Ni2+、Fe3+、Fe2+、Ru3+、Ag+)和碱金属离子(K+、Na+、Li+)进行高灵敏度检测方面的研究进展,并对该领域的发展前景进行了展望。 相似文献
76.
Donald J. Darensbourg Floyd A. Beckford Joseph H. Reibenspies 《Journal of Cluster Science》2000,11(1):95-107
The syntheses of Ru3(CO)9(PTA)3 and Ir4(CO)7(PTA)5 were accomplished through the thermal reactions of Ru3(CO)12 or Ir4(CO)12 with the water-soluble phosphine, PTA(1,3,5-triaza-7-phosphaadamantane). The ruthenium derivative was shown by X-ray crystallography to consist of a triangular Ru3 core with three nearly equal Ru–Ru bonds, with each ruthenium atom bearing an equatorially positioned PTA ligand. In Ir4(CO)7(PTA)5 the iridium atoms define a tetrahedron which is bridged on three edges by CO ligands. One basal iridium atom contains two PTA ligands, while the other two basal and the apical iridium atoms each possess one PTA ligand in their coordination spheres. Although, Ru3(CO)9(PTA)3 is only sparingly soluble in pure water, it is very soluble in aqueous solution of pH<4. Indeed the triruthenium cluster can be extracted reversibly between an aqueous and an organic phase (e.g., CH2Cl2) by changing the pH of the aqueous phase. On the other hand the more highly PTA substituted cluster, Ir4(CO)7(PTA)5, exhibits good solubility in aqueous solution (pH 7 and below) and a variety of organic solvents. Both cluster derivatives are stable in deoxygenated, aqueous solutions for extended period of time (>24 h). 相似文献
77.
78.
Hyo-Jin Kang Eun-Hee Kang Sang-Wook Park Jae-Wook Lee Jin- Kook Lee 《Macromolecular Symposia》2006,235(1):195-200
Summary: Polyethylene glycol substituted titanyl phthalocyanine was prepared in two steps starting from phthalonitrile and characterized by FT-IR, UV-vis spectrophotometry, and fluorescence spectrophotometry. The titanyl phthocyanine derivatives (TiOPcs) showed high solubility in common organic solvents, such as, CH3Cl and DMF. These compounds decreased in absorbance intensity with increase of molecular weight of polyethylene glycol at maxima wavelength of visible range. The fluorescence spectra showed a fluorescence emission near 690 nm with a quantum yield of 0.05–0.32 (λex = 625 nm). 相似文献
79.
采用新型Salen中间体合成了新型Salen Zn(II)配合物. 用紫外-可见光谱滴定法研究了主体双核Salen Zn(II)与咪唑、二胺类等含氮小分子的分子识别行为, 测定了它们的缔合常数. 对咪唑类客体的缔合常数顺序为Kθ(Im)>Kθ(2-MeIm)>Kθ(EMeIm); 对二胺类客体缔合常数顺序为Kθ(DAP)>Kθ(DAE). 主体与咪唑类和二胺类客体的配位数分别是2和1. 主体与这些客体的识别过程为放热、熵减的焓驱动反应. 利用圆二色光谱研究了识别过程的Cotton效应. 用分子力学方法研究了主客体体系的最低能量构型, 通过量化计算对实验事实做了进一步解释. 相似文献
80.
毛细管电泳法高压快速分离分析菠菜中的水溶性维生素 总被引:1,自引:0,他引:1
在毛细管电泳法中,通过双模对接高压电源可以获得0~40 kV甚至40 kV以上的超高电压。本研究在40 kV的超高电压下,以纯电解质水溶液为缓冲液,实现了蔬菜中通常含有的8种水溶性维生素(VB1、VB2、VB6、VC、D-泛酸钙、D-生物素、烟酸和叶酸)的快速分离及菠菜样品的定量分析。通过考察电压、缓冲溶液浓度、pH值等因素对分离的影响,确定了优化的实验条件。结果表明,在40 kV高压下,采用25 mmol/L硼砂-硼酸溶液缓冲液(pH 8.8),菠菜中上述8种水溶性维生素在2.2 min内获得了较好的基线分离。用此方法对菠菜中的水溶性维生素进行定量分析,得到了令人满意的结果。水溶性维生素的线性相关系数范围为0.9981~0.9999,检出限为0.2~0.3 mg/L,在菠菜中的平均加标回收率为88.0%~100.6%,峰面积的相对标准偏差(RSD)为1.15%~4.13%。 相似文献