共查询到20条相似文献,搜索用时 9 毫秒
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壳聚糖支载有机荧光染料可在生理条件下改变其荧光特性,本文采用壳聚糖(CTS)支载有机荧光染料Cy3,利用红外光谱和热分析对产物进行了表征,研究了壳聚糖支载的荧光染料紫外吸收光谱和荧光光谱特性,结果表明,壳聚糖支载的荧光染料Cy3的紫外吸收特征峰的波长无明显变化,荧光强度明显增强,支载后的荧光染料光稳定性良好,初步细胞标记实验显示,壳聚糖支载后的Cy3染料对脑胶质瘤细胞具有良好的亲和性,并能穿透细胞膜且发出明显荧光。 相似文献
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Organic fluorescent dyes are widely used in single molecule localization microscopy, where their performances are determined by the photophysical properties. Herein, we utilized a sensitive method to modulate the fluorescence of organic dyes by external potentials using a combination of electrochemical cell and super‐resolution fluorescent microscopy. Cy5 (cyanine dye) was chosen as a model molecule considering its wide application and commercial availability. We applied different potentials on the Au electrode to change the Coulombic charge microenvironment of Cy5. When the electrode potential was adjusted negatively, Cy5 displayed a better photostability. This method is proved effective in adjusting the fluorescence of organic dyes. 相似文献
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Morozov V. N. Klimovich M. A. Kolyvanova M. A. Dement’eva O. V. Rudoy V. M. Kuzmin V. A. 《High Energy Chemistry》2021,55(5):341-348
High Energy Chemistry - Structural changes in particles of cholesteric liquid crystal dispersion (CLCD) of DNA during the formation of complexes of the cyanine dyes SYBR Green I (SG) and PicoGreen... 相似文献
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为考察小分子配基与不同核酸结构的结合机理,发展新的核酸探针分子,合成了一种新型一次甲基不对称菁染料(MTP).吸收光谱、荧光光谱及圆二色光谱研究结果表明,MTP可与平行和混合平行G-四链体DNA(如c-myc和22AGK+)较强地结合,并引起130~180倍的荧光增强;其与单/双链DNA作用较弱,导致40~60倍荧光增强;而与反平行G-四链体DNA(如TBA和22AGNa+)的作用最弱,只引起15~25倍荧光增强;以上结果表明MTP可作为荧光探针分子用于区别不同结构的核酸分子.结合机理研究表明,平行和混合平行G-四链体DNA优先通过沟槽结合模式结合1分子MTP,再通过末端堆积模式结合另1分子MTP. 相似文献
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It was found that the chemiluminescence of acridinium ester (AE) was quenched effectively by gold nanoparticles (AuNPs) with Stern-Volmer constants approaching 10(10) M(-1), which was exploited to realize sequence-specific DNA detection based on the preferential absorption of AE-tagged single-strand probe on unmodified AuNPs over the hybrids of probe and target DNA. 相似文献
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E. S. Lisitsyna O. N. Lygo N. A. Durandin O. V. Dement’eva V. M. Rudoi V. A. Kuzmin 《High Energy Chemistry》2012,46(6):363-367
The influence of gold nanoparticles (diameter of about 2.5 nm) on the complex between the SYBRGreen dye and double-stranded DNA in solutions has been investigated by fluorescence spectroscopy. Strong quenching of dye fluorescence by nanosized gold particles (??superquenching??), characterized by a high Stern-Volmer constant of K SV ?? 3.3 × 107 L/mol, has been found. The superquenching effect in the test system is explained in terms of contribution of several processes: electron transfer, formation of aggregates of gold nanoparticles involving dye dications, and enhancement of intersystem crossing by a heavy atom (gold atoms of nanoparticles). 相似文献
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N,N′-对羧苄基吲哚三菁敏化纳米TiO2电极的研究 总被引:1,自引:0,他引:1
应用光电化学方法研究了N, N′-对羧苄基吲哚三菁(Cy5)染料敏化TiO2纳米晶电极的光电化学行为,优化了敏化的条件.结合Cy5的循环伏安曲线和光吸收阈值,初步确定Cy5电子基态和激发态能级位置.结果表明,Cy5电子激发态能级位置能与TiO2纳米粒子导带边位置相匹配,因而使用该染料敏化可以显著提高TiO2纳米晶的光电流,使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区,光电转换效率得到明显改善,在膜厚为6.5μm、敏化时间为6 h的条件下IPCE值(incident photo-to-electricity conversion efficiency)最高可达46.4%,总的光电转换效率η为1.70%. 相似文献
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基于花青染料3-乙基-2-[7-(3-乙基-2-苯并噻唑啉)-1,3,5-庚三烯]碘化苯并噻唑与DNA杂交双链的特异性结合作用,将DNA的杂交信号转化为染料在可见光区的光吸收信号。实验结果表明,与DNA杂交双链结合后,该染料在760nm处产生强吸收峰,吸光度数值及其稳定性受杂交链长度和体系温度的影响。在25℃条件下,采用24-mer探针,可以检测mg·mL-1数量级的互补DNA链,比DNA自身杂交信号灵敏度提高两个数量级。在优化实验条件下,利用该染料还可识别短链DNA中存在的单核苷酸多态性。与其它DNA片段的检测以及单核苷酸多态性的识别方法相比,该方法更为简便迅速,在临床诊疗中具有潜在的应用价值。 相似文献
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半胱氨酸是生物体中起着重要作用的还原性氨基酸,其在体内的含量变化可能会诱发机体发生多种病变。因此高选择性、高灵敏度和低成本的半胱氨酸检测技术具有重要意义。目前,高效的半胱氨酸检测方法有毛细管电泳、质谱、高效液相色谱和表面增强拉曼散射等,这些方法往往需要复杂的样品制备和精细的实验仪器,可能会限制其在半胱氨酸检测中的应用。本文利用富含鸟嘌呤的DNA链序列在钾、钠等金属离子诱导下形成对汞离子产生特殊响应的二级结构,而菁染料能够对DNA结构进行识别,并由此引起其超分子聚集形式的改变,致使其紫外和可见光谱性质随之变化。最终以Hg2+调控G-四链体与菁染料(ETC)组建的传感器,实现对溶液体系中半胱氨酸高选择性的快速可视化检测。 相似文献
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IntroductionThereisconsiderableteclndcalinterestillcyallilledyeswitllabsorptionInakilnaintilenear-infraredregion,principallybecauseoftheirpotelltialapplicationinareassuchaslaserandopticaldaisstorageteclmology'.However,tileligllifastnesspropertiesofcyaninedyesarenotasgoodasUloseoftileoillerdyes,i.e.Uleyareeasilypllotooxidized.Therefore,itisverysignificanttostudytilepllotooxidationofcyaninedyes.WehavepreviouslyreportedaseriesofstudiesOilhlepllotofadingofsomefunctionalcyaninedyes'.'.RecentstUd… 相似文献
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用光电化学方法研究了不对称菁类染料敏化TiO2纳米结构电极的光电转换过程.结果表明,该染料的电子激发态能级位置与TiO2纳米粒子导带边位置匹配较好,光激发染料后,其激发态电子可以注入到TiO2纳米多孔膜的导带,从而使TiO2纳米结构电极的吸收光谱和光电流谱红移至可见光区,其 IPCE(Incident photon-to-electron conversion efficiency)值最高可达84.3%.并进一步结合现场紫外-可见吸收光谱研究了外加电势对激发态染料往TiO2纳米多孔膜注入电子过程的影响. 相似文献
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采用飞秒荧光上转换技术,研究了阴阳离子菁染料及对应的阴离子和阳离子菁染料吸附在立方型和T型溴碘化银表面上形成J-聚集体的荧光衰减时间分辨特性,分析了几种菁染料增感体系的超快电子转移动力学过程及其对增感效率的影响.通过比较几种菁染料增感体系的荧光衰减特性,两种阴阳离子染料要明显快于阴离子染料、阳离子染料及二者的加合,说明阴阳离子染料聚集体到溴碘化银的电子注入速率较快,增感效果更好.对两种阴阳离子染料聚集体荧光衰减特性的比较,可以看出染料在T型颗粒溴碘化银上形成聚集体的荧光寿命更短,因而对T型颗粒的增感效果更好.染料Dye2的荧光衰减要快于染料Dye1,说明染料Dye2到溴碘化银的电子注入速率更快,增感效率更高. 相似文献
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The trans-cis photoisomerization of pentamethine cyanine dye (Cy5) has been theoretically investigated by the analysis on an analogical molecule model. All possible isomers have been searched by rotating the different bridge C-C bonds of the model. The relative stability of the isomers for the ground and first excited states as well as the corresponding excitation mechanism has been envisaged by DFT and time-dependent DFT method. The results show different conjugation degree of the isomers resulting in different absorption energy upon the different C-C bridge bond rotation. From the analyses of electronic density distribution of the frontier orbitals, it is predicted that there is charge transfer besides the π-π* excitation for the cyanine dye model, which makes the mechanism and photo-properties different form those of other conjugated molecules. 相似文献