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SURFACE CAPPING OF TiO2 COLLOIDAL NANOPARTICLES STUDIED BY FOURIER TRANSFORM RAMAN SPECTRA 下载免费PDF全文
Surface capping of TiO2 colloid nanoparticles with tetrasulfonated gallium phthalocyanine chloride (GaTsPc) was studied by Fourier Transform (FT) Raman spectra. A striking FT-Raman signal enhancement of GaTsPc is observed, indicating that a surface complex is formed during surface capping of GaTsPc dye molecules on TiO2 colloid via sulfonate groups. This effect is attributed to a strong Raman resonance with the charge transfer transition in the surface complex. Surface complexation also have considerable influences on the FT-Raman signals for TiO2 nanoparticles. 相似文献
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绿荧光蛋白的双光子激发的荧光特性研究 总被引:1,自引:0,他引:1
利用双光子激发方式研究了重组绿荧光蛋白(recombinant green fluorescent protein,简称rGFP)的光转换特性,研究结果表明rGFP具有较强的双光子激发荧光,双光子激发的荧光偏振光谱表明rGFP在辐照前质子态和去质态之间存在着有效的能量转移过程,rGFP辐照后导致生色团构象的变化,部分阻断了rGFP内源的氨基酸与生色团之间的能量转移过程,导致rGFP的双光子激发的荧光强度下降,观察到rGFP的三光子激发的荧光特性,这种三光子激发的荧光主要来源于rGFP内源的氨基酸(色氨酸,酪氨酸等)的吸收。研究结果对在实际使用定量的光显微镜时具有一定的指导意义。 相似文献
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The zinc-blende CdS nanocrystals with particle size less than 10nm were prepared in solution with a molecular surfactant. The particle surface was modified with capping molecules, bis(2-ethylhexyl) sulfosuccinate disodium salt (AOT) or hexametaphosphate (HMP). The colloid solution was deposited on silicon wafer and the assembly of these nanocrystals was studied by atomic force microscopy. It was found that the CdS/AOT formed a monolayer by simply dropping the colloid solution on silicon surface, while CdS/HMP exhibited 3D structure with prefered orientation in the similar deposition process. A dynamic electric force microscopy was performed and the polarizability was measured from the resonance of cantilever under applied alternating voltage between tip and substrate. The dielectric constant of CdS nanocrystal was estimated by comparing the different electric capacitance of Au and CdS nanocrystals. 相似文献
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用不锈钢/电沉积紫膜薄膜/含水胶(电介质)/钢型菌紫质光电池研究了作用于N-端表面(紫膜外表面)的钾、镁、镧离子对菌紫质光电响应的影响。在所测条件下光电极性均与质子泵方向一致。光电压幅值是离子浓度依赖性的,对钾、镁、镧离子均存在极大值浓度,它们之间有数量级的差异;依赖性曲线趋势和极大值浓度均各自分别与溶液中菌紫质的质子泵效率对阳离子浓度的这种依赖性相一致。不过,光电响应对作用于C-端表面的这些离子不存在上述的浓度依赖性。上述的两种依赖性成相关性说明:电沉积紫膜薄膜中菌紫质的光电响应主要来自质子泵运而非非质子离子的贡献;存在一合适的离子浓度使菌紫质的光电响应有极大值。用质子泵结构域模型和扩散双电层理论对这种依赖性进行的讨论认为:金属阳离子的结合与屏蔽两种效应可以解释这种依赖性。 相似文献
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发光标记分析及其在核酸检测中的应用 总被引:11,自引:0,他引:11
综述了化学发光,生物发光,电致化学发光中最重要的发光体系,增强鲁米诺体系,吖啶酯发光体系,碱性磷酸酶/1,2-二氧环乙烷体系,荧火虫荧光素/荧光素酶及联吡啶钌发光体系的原理,标记检测方法,最近的进展及在核酸领域的应用,对近年来新发展的发光标记方法作了介绍并分析了该领域今后可能的研究方向。 相似文献
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研究了分子印章法DNA芯片在片合成技术中的压印化学合成过程,提出了压印偶联反应和压印脱二对甲氧基三苯基阳离子(DMT)反应合成寡核苷酸的2种方案,并对其合成产率的差异进行了比较.由于单次压印偶联反应比压印脱DMT反应合成效率高且所需时间短,故选择压印偶联反应来合成寡核苷酸及其阵列并对其工艺进行了优化.实验表明压印偶联反应的合成效率高,从第6个核苷开始偶联效率接近100%;压印2次比压印1次的偶联效率高且更均匀;压印3次及3次以上除更均匀外对偶联效率的改善不明显;玻璃载片经多次压印后对偶联反应的影响不大.用压印偶联反应的方法成功合成出20 mer的寡核苷酸探针. 相似文献
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