Induced circular dichroism and laser action of hemicyanine dyes coupled to DNA and DNA-complex
Induced circular dichroism and laser action of hemicyanine dyes coupled to DNA and DNA-complex
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DOI：
10.1117/12.2277394
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发表时间：
2017-10
期刊：
影响因子：
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通讯作者：
Y. Kawabe;Yuki Suzuki;T. Tanaka;K. Okoshi
中科院分区：
文献类型：
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作者：
Y. Kawabe;Yuki Suzuki;T. Tanaka;K. Okoshi
许多有机染料体系与DNA或DNA-表面活性剂复合物的偶联可诱导强荧光增强，促进了薄膜激光器件的发展。由于染料的荧光特性对相互作用模式非常敏感，因此有必要详细阐述它们与DNA及其复合物相互作用时的光学性质。在这项研究中，吸收和圆二色性（CD）光谱的解决方案溶解半菁和DNA或其复合物进行了检查，并与不同的方法制备的复合物薄膜的激光发射的细节进行了研究。染料与纯DNA的相互作用使其吸收光谱发生明显变化，而DNA复合物使染料的荧光发射过程发生蓝移。在染料吸收带的诱导CD光谱中的Clear Cotton效应表明与纯DNA的直接相互作用可能是由于沟结合。同时，染料与DNA复合物混合后的CD信号较弱，表明它们之间存在间接的相互作用。激光振荡特性取决于薄膜的形成方法。最近发展的“浸没”工艺提供了在布居光栅光泵浦下显示出强激光发射的薄膜器件。初始输出强度是两个数量级以上，从常规制备的薄膜。在三种半菁染料中获得了低阈值和长寿命的浸没式器件，使其具有未来应用的前景。
Strong fluorescence enhancement is induced for many organic dye systems by the coupling to DNA or DNA-surfactant complex, prompting the development of thin film laser devices. Since fluorescence characteristics of the dyes are very sensitive to the interaction mode, it is worthwhile to elaborate their optical properties when interacting with DNA and its complexes. In this study, absorption and circular dichroic (CD) spectra were examined for solutions dissolving hemicyanines and DNA or its complex, and the details of laser emission were studied with the complex films prepared by different methods. Absorption spectra for the dyes changed remarkably by the interaction with pure DNA, while DNA-complex caused blue shift in fluorescence emission process. Clear Cotton effect in induced CD spectra in the dye absorption band indicated the direct interaction with pure DNA presumably due to groove binding. Meanwhile, relatively weak CD signal from the dyes mixed with DNA-complex suggested indirect interaction mode between them. Laser oscillation properties depended on the film formation method. Recently-developed ‘immersion’ process provided thin film devices which showed strong laser emission under optical pumping with population grating. Initial output intensity was two orders of magnitude greater than that from conventionally prepared films. Low threshold and long durability of the immersion made devices were obtained in three types of hemicyanine dyes, making them promising for future application.