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

描述（由申请人提供）：量子点具有革命性的生物成像由于其特殊的生物物理特性的潜力。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。用于制备QD-生物分子缀合物的常见策略产生具有不明确的化合价、相对大的流体动力学尺寸和有限的模块性的产物。为了解决这些问题，从而建立更高性能和更通用的量子点成像探针，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阻寡核苷酸，其被设计为在QD反应时包裹QD，从而将反应的程度限制在固定化合价的种类。我们提出（i）将QD单步完全转化为小（< 12 nm）、模块化、高度特异性和单价的生物成像探针;和（ii）通过阐明Notch及其在活细胞表面上的加工中间体的动力学来证明这些探针在具有挑战性的单分子成像应用中的效用。最终，我们建议将量子点从“特殊用途的探针”转变为“多功能和随时可用的生物探针”，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.