量子点双光子激发FRET新方法及其生物分析应用

项目名称： 量子点双光子激发FRET新方法及其生物分析应用

项目编号： No.21205043

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 分析化学

项目作者： 刘玲芝

作者单位： 华中农业大学

项目金额： 25万元

中文摘要： 双光子激发-荧光共振能量转移(FRET)技术能够避免生物样品自身荧光和散射光的干扰，减少对生物样品的光损伤，适用于复杂生物样品分析。然而双光子激发FRET的分析性能诸如检测的灵敏度等会受到有机荧光染料和荧光蛋白较小双光子活性截面的限制。本项目以常见的生物大分子：肿瘤标志物、病毒DNA为模型化合物，控制合成双光子活性截面大、生物相容性好的核壳型量子点，利用链霉亲和素-生物素识别等方式实现量子点与生物大分子的可控偶联，通过检测量子点双光子激发荧光信号的变化，深入研究以量子点为供体的双光子激发FRET技术在复杂生物样品分析中的应用，阐明量子点的双光子激发性质与壳层结构、壳层厚度、粒径大小之间的关系，从分子水平上揭示量子点双光子激发FRET技术在生物医学分析中的优越性。本项目利用量子点大的双光子活性截面提高双光子激发FRET在实际生物样品分析中的灵敏度，对拓宽FRET的应用领域具有重要的意义。

中文关键词： 量子点；双光子激发；比率型；碳点；相互作用

英文摘要： Two-photon excited fluorescence resonance energy transfer (TPE-FRET) can eliminate the autofluorescence of biomolecules and the scattered excitation light. Besides, the IR light causes much less photobleaching off the focal plane and less photodamage to biological samples, indicating the usefulness of TPE-FRET in complicated biological sample matrix. However, FRET performance driven by a two-photon excitation process has been limited by the photophysical properties of organic dyes and fluorescent proteins. Considering the large two-photon action cross-section of quantum dots (QDs), this proposal is proposed to develop TPE-FRET technique with QDs as donor and construct several model assays for tumor markers and viral DNA to demonstrate the merits of TPE-FRET based bioassays. Colloidal core/shell QDs with large two-photon action cross-section, good biological compatibility will be synthesized and conjugated to biomolecules via biotin-streptavidin bridge. The effects of shell structure, shell thickness, as well as size on two-photon absorption of core/shell QDs will be investigated and the applicability of TPE-FRET technique with quantum dot as donor in complicated biological sample matrix will be studied by detecting the two-photon excited fluorescence of QDs. The results of this proposal will contribute to the de

英文关键词： quantum dots；two-photon excitation；ratiometric；carbon dots；interaction