Small, modular, and monovalent Quantum Dots for single molecule imaging of Notch

描述(申请人提供)：量子点具有特殊的光物理性质，有可能使生物成像发生革命性的变化。然而，精确控制量子点和其他生物分子之间的界面化学仍然是一个重大的合成挑战，限制了它们在生物学中的广泛应用。常用的制备QD-生物分子偶联物的策略所产生的产物的价态定义不明确，流体力学尺寸相对较大，以及有限的模块化。为了解决这些问题，从而建立更高性能和更多功能的量子点成像探针，我们提出了一种创新的合成方法，称为空间排斥。该方法使用官能化的空间排斥寡核苷酸，设计用于在QD反应时包裹QD，从而将反应的程度限制为固定价态的物种。我们建议(I)一步完成量子点到生物成像探针的转换，这些探针是小的(12 Nm)、模块化的、高度特异的和单价的；(Ii)通过阐明活细胞表面Notch及其加工中间体的动力学，展示这些探针在具有挑战性的单分子成像应用中的用途。最终，我们建议将量子点从“特殊用途的探测器”转变为“多功能的、随时可用的生物探测器”，任何学科的科学家都可以使用。

DESCRIPTION (provided by applicant): Quantum dots have the potential to revolutionize biological imaging due to their exceptional photophysical properties. However, precise control over the interfacial chemistry between QDs and other biomolecules remains a significant synthetic challenge limiting their broad application in biology. Common strategies for preparing QD-biomolecule conjugates generate products with poorly defined valency, relatively large hydrodynamic size, and limited modularity. To address these issues and hence to establish higher-performance and more versatile QD imaging probes, we propose an innovative synthetic approach, termed "steric exclusion". The method uses a functionalized steric-exclusion oligonucleotide designed to wrap the QD as it reacts and thereby limits the extent of the reaction to a species of fixed valency. We propose to (i) perform the single-step complete conversion of QDs to bioimaging probes that are small (< 12 nm), modular, highly-specific, and monovalent; and (ii) demonstrate the utility of these probes in a challenging single- molecule imaging application by elucidating the dynamics of Notch and its processing intermediates on the surface of live cells. Ultimately, we propose to transform QDs from "probes for special purposes" to "versatile and ready-to-use bioprobes," accessible to scientists from any discipline.