EAGER: New Ligand Shells for Small Quantum Dots

智力上的优点。 当蛋白质用报告标记物标记以追踪蛋白质在细胞上或细胞内的位置和运动时，标记物的物理尺寸可能非常重要。这对于被称为量子点（qdots）的流行标签类别尤其如此，量子点是具有强烈荧光的无机晶体。量子点的核心相当小，2-4 nm，但完全不溶。为了使它们可溶于水基缓冲液中，需要疏水-亲水配体壳。市售量子点的直径通常为21 nm。 这项研究将制作一个只有2纳米厚的配体屏蔽层。防护层将有一个硫原子，它将量子点核心紧紧地结合在一起。该硫将是硫醇、硫醚或硫酮。 这种硫也将有聚乙二醇，使实体水溶性。它可能具有负电荷或正电荷，以减少非特异性粘附。最后，它将有一个生物活性实体进行耦合。量子点具有巨大的潜力，作为标记蛋白质的令人难以置信的明亮荧光团。然而，它们的大尺寸限制了它们作为生物示踪剂的有用性。本文提出的研究旨在通过向研究界提供方法来克服这一限制，以制造一类新的水溶性量子点，这些量子点明显小于目前市售的量子点。这项研究为合成化学家和对基础光学、显微镜和光谱学感兴趣的研究生提供了很好的培训。

Intellectual merit. When proteins are tagged with reporter labels to trace the locations and movements of the proteins on or within cells, the physical size of the label can be quite significant. This is especially true for the popular class of labels called quantum dots (qdots), which are inorganic crystals with intense fluorescence. The core of a qdot is fairly small, 2-4 nm, but is completely insoluble. To make them soluble in water-based buffers requires a hydrophobic-hydrophilic ligand shell. Commercially-available qdots are typically 21 nm in diameter. The research will make a ligand-shield that is only about 2 nm thick. The shield will have a sulfur atom that binds the qdot-core very tightly. This sulfur will either be a thiol, a thioether, or a thioketone. This sulfur will also have a polyethylene glycol, making the entity water soluble. It may have a negative or positive charge to reduce non-specific sticking. Finally, it will have a bioreactive entity for coupling.Broader Impacts. Quantum dots have tremendous potential as incredibly bright fluorophores for labeling proteins. However, their large size has limited their usefulness as biological tracers. The research presented here intends to overcome this limitation by providing to the research community methods to make a new class of water-soluble quantum dots that are significantly smaller than those currently commercially available. The research provides excellent training for synthetic chemists and graduate students who are interested in basic optics, microscopy, and spectroscopy.