Luminescent Probes of DNA and Semiconductor Surface Structure

南卡罗来纳大学的凯瑟琳·J·墨菲博士获得了无机化学、生物无机化学和有机金属化学项目的支持，该项目获得了学院早期职业发展奖，以研究利用发光作为表面结构的探针。目标有三个方面：(1)三亚胺Ru(II)配合物将被设计成只有当其中一个二亚胺配体具有合适的长度以适合由于三级结构而形成的DNA等大分子中的空穴时才能观察到发光。(2)已知的硫化镉“量子点”发光对表面吸附物质的性质和数量的敏感性，将作为确定DNA与这些颗粒相互作用的性质的一种手段。可以假设，可以弯曲的DNA会吸附到合适直径的颗粒上，这种吸附可以通过颗粒发光的变化来监测。包裹在适当大小颗粒周围的DNA分子两端之间的距离可以通过双链两端(荧光素和罗丹明)上的分子标签之间的能量转移的程度来进一步研究。(3)将尝试合成中空的“量子点”硫化镉颗粒，以努力模拟报告的多孔半导体颗粒的发光。这些粒子的光学/结构关系将被用来开发一个多孔半导体的电子结构模型。该教学计划概述了通过正规课程工作以及通过本科生和研究生研究将材料化学引入本科生和研究生课程的几种方式。还详细介绍了通过与校园内以及当地高中和中学的妇女组织互动来促进女科学家发展的计划。发光是某些分子的一种独特性质，在这种分子中，光的吸收导致光的发射，通常是较长波长的光。这种发光的波长和强度通常对吸收分子的环境非常敏感。这项研究旨在利用几种材料的发光来探测其环境的结构。这些应用可能提供关于某些类型的DNA结构的独特信息，这是其他技术不容易确定的。该教学计划旨在增加本科生和研究生接触材料化学的机会，并促进女性科学家的发展。

Dr. Catherine J. Murphy, of the University of South Carolina, is supported by the Inorganic, Bioinorganic and Organometallic Chemistry Program under a Faculty Early Career Advancement Award for the study of uses of luminescence as a probe of surface structure. Three areas are targeted: (1) Trisdiimine ruthenium(II) complexes will be designed such that luminescence will be observed only when one of the diimine ligands is of the appropriate length to fit a cavity in a large molecule such as DNA that is formed as a result of tertiary structure. (2) The known sensitivity of the luminescence of "quantum dots" of cadmium sulfide to the nature and amount of surface adsorbate will be investigated as a means of determining the nature of the interaction of DNA with these particles. It is hypothesized that DNA that can bend will adsorb to particles that are of the appropriate diameter and that this adsorption can be monitored by changes in the luminescence of the particles. Distances between the ends of DNA molecules wrapped about suitably sized particles may be further investigated by the extent to which energy transfer between molecular tags on the two ends of the duplex (fluorescein and rhodamine) occurs. (3) Synthesis of hollow "quantum dot" cadmium sulfide particles will be attempted in an effort to model the luminescence reported for porous semiconductor particles. Optical/structure relationships for these particles will be used to develop a model for the electronic structure of porous semiconductors. The teaching plan outlines several ways in which materials chemistry will be introduced into the undergraduate and graduate curricula through formal course work and through both undergraduate and graduate research. Also detailed are plans to foster the development of female scientists through interactions with women's organizations on campus and in local high schools and middle schools. Luminescence is a unique property of certain classes of molecules in whic h the absorption of light results in emission of light, usually of a longer wavelength. The wavelength and intensity of such luminescence is generally very sensitive to the environment about the absorbing molecule. This research aims to utilize the luminescence of several materials to probe the structures of their environments. These applications may provide unique information about the structure of certain types of DNA that is not readily determined by other techniques. The teaching program is designed to increase the exposure of undergraduate and graduate students to materials chemistry and to foster the development of female scientists.