EAGER: New Ligand Shells for Small Quantum Dots

知识价值。当用报告标记标记蛋白质以追踪蛋白质在细胞上或细胞内的位置和运动时，标记的物理大小可能相当重要。这对于被称为量子点（qdots）的标签来说尤其如此，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纳米，但完全不溶。为了使它们可溶于水性缓冲液，需要疏水-亲水性配体外壳。商业上可用的量子点通常直径为21纳米。这项研究将制造一种只有2纳米厚的配体屏蔽。屏蔽层会有一个硫原子将量子点核紧紧地束缚在一起。这个硫要么是硫醇，要么是硫醚，要么是硫酮。这个硫也会有一个聚乙二醇，使得这个实体是水溶性的。它可能带有负电荷或正电荷，以减少非特异性粘着。最后，它将具有生物反应性实体进行耦合。更广泛的影响。量子点具有巨大的潜力，可以作为非常明亮的荧光团来标记蛋白质。然而，它们的大尺寸限制了它们作为生物示踪剂的用途。本文提出的研究旨在通过向研究界提供制造新型水溶性量子点的方法来克服这一限制，这种量子点比目前市售的量子点要小得多。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极好的培训。

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.