排序方式: 共有95条查询结果,搜索用时 15 毫秒
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Liu J Wang X Wang L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(1):32-35
A new simple, selective and sensitive fluorescence quenching method was developed to determine nucleic acids (DNA) with the 9-anthracenecarboxylic acid (ACA)-cetyl trimethyl-ammonium bromide (CTAB) system. The fluorescence intensity of ACA was decreased by the addition (CTAB). However, the fluorescence intensity of the system increased dramatically when DNA was added to the solution. The fluorescence enhancement is probably based on the DNA interaction with CTAB. Under the optimum conditions, the changes of fluorescence intensity in the absence and presence of nucleic acids was proportional to the concentration of nucleic acids over the range 0.08-1.0 microg mL(-1) for CT (calf thymus) DNA or FS (fish sperm) DNA. Its detection limits are 0.02 microg mL(-1) for CT DNA and 0.019 microg mL(-1) for FS DNA. Based on this approach, a new quantitative method for DNA assay is presented in this paper. 相似文献
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不对称氢化硅烷化可实现由含碳碳或碳杂双键的化合物合成手性醇和手性腹,在石油化工、药物合成、生物碱等生物活性物质的合成等领域具有潜在的应用价值.90年代以来,不断有高活性、高选择性的手性催化剂的开发研究报道[‘-‘],使不对称硅氢化研究成为催化科学的一个研究方向.我们开展了带有毗吹取代基的座隆烷类手性络合催化剂的研究工作D·‘’.a一毗院甲醛、L一半就氨酸甲酯盐酸盐、氯化环辛M烯合#[Rh(COD)CI」。以及Ph2SIH。按文献[7j制备,苯乙酮为分析纯试剂.所用仪器有SP--2305型气相色谱仪,170SX-FTIR型… 相似文献
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Novel fluorescent colloids as a DNA fluorescence probe 总被引:1,自引:0,他引:1
Fluorescent perylene colloids in the 80–90 nm size range have been prepared by the reprecipitation method. These nanoparticles were modified by cetyltrimethylammonium bromide (CTAB) which inhibited their growth. The nanoparticles also readily interacted with DNA. The fluorescence emission was measured at ex/em=400/565 nm. The fluorescence decrease of colloid–CTAB in aqueous solution was measured in the presence of nucleic acids. Under the optimum conditions, the ratio of fluorescence intensity in the absence and presence of nucleic acids was proportional to the concentration of nucleic acids over the range 0.02–5.1 µg mL–1 for FS (fish sperm) DNA or CT (calf thymus) DNA. The detection limits were 0.01 µg mL–1 for FS DNA and 0.012 µg mL–1 for CT DNA, respectively. Based on this approach, a new quantitative method for DNA assay is presented in this paper. 相似文献
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Preparation and application of a novel core/shell organic nanoparticle as a fluorescence probe in the selective determination of Cr(VI) 总被引:1,自引:0,他引:1
Wang L Xia T Liu J Wang L Chen H Dong L Bian G 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2005,62(1-3):565-569
A novel core/shell organic nanoparticles, anthracene/poly-acrylamide (AN/PAM), has been prepared successfully. Based on the fluorescence quenching of AN/PAM nanoparticles by Cr(VI), a method for the selective determination of Cr(VI), without separation of Cr(VI) in water, was developed. Furthermore, the reaction mechanism between nano-AN/PAM and Cr(VI) was also discussed. The synthesis and reaction conditions were investigated in detail. The assay is characterized by short reaction time, very few interference stable fluorescence signals, simple instruments and sensitivity. Under optical experimental conditions, a limit of detection of 0.02 microg/ml was achieved. The calibration curve was linear over the concentration range 0.04-2.00 microg/ml with a correlation coefficient of 0.9924. The proposed method has been applied to the selective quantification of Cr(VI) in synthetic samples and waste-water samples with the satisfactory results. 相似文献
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