Chiral nanoparticles: preparation and studies of their optical properties and self-assembly into functional nanocomposite materials

手性是所有物体的固有属性，无论是宏观的，如左右手，还是微观的，如分子。手性在化学中非常重要，因为大多数天然分子都是手性的。然而，在纳米尺度上，尤其是纳米粒子，手性仍然很大程度上未被充分探索。了解和控制纳米颗粒手性至关重要，并将立即影响手性材料在催化和生物传感器中的应用。拟议研究的愿望是发现和研究制备手性纳米颗粒的有效途径。实现对纳米粒子手性的控制，并将其与对纳米粒子的尺寸、多分散性和表面功能的控制相结合，将使它们能够作为具有可调节功能特性的纳米复合材料的手性构件。最近，我的实验室生产出了具有突出手性和胶体稳定性的金纳米颗粒。在我们现阶段的研究中，手性纳米颗粒的形成机制有待详细研究。大多数纳米颗粒表现出尺寸依赖性光学特性（“量子尺寸”效应），因此拉曼和紫外-可见显微光谱的结合将用于对纳米颗粒形成进行灵敏的原位监测。我们还将探索手性纳米颗粒的自组装并将其纳入合适的基质中，以生产具有受控手性和纳米级结构的新型复合材料。此类材料在先进光学应用中很有前景，例如超材料。  具有受控手性、表面功能和选择性光学响应的​​材料是生物传感器的自然选择。它们可以定制来检测极少量的目标分子，因为与散装材料相比，纳米颗粒的特性对表面变化更加敏感。手性纳米粒子有利于对映选择性催化，目前的重点是有效合成类似于天然化合物的分子。因此，我们的研究将致力于生产用于催化剂和传感器的纳米复合材料。

Chirality is an inherent property of all objects, be they macroscopic, such as right and left hands, or microscopic, like molecules. Chirality is very important in chemistry since most natural molecules are chiral. Yet, chirality still remains largely underexplored at the nanoscale, and especially for nanoparticles. Understanding and controlling nanoparticle chirality is of fundamental importance and will immediately impact applications of chiral materials in catalysis and biosensors. The aspiration of the proposed research is to discover and study efficient routes of preparation of chiral nanoparticles. Attaining control over nanoparticle chirality and combining it with control over size, polydispersity and surface functionalities of nanoparticles will enable their applications as chiral building blocks for nanocomposite materials with tunable functional properties. Recently, gold nanoparticles featuring prominent chirality and colloidal stability have been produced in my laboratory. At the current stage of our research, the mechanisms of chiral nanoparticle formation are to be investigated in detail. Most nanoparticles display size-dependent optical properties ("quantum size" effect), so the combination of Raman and UV-Vis microspectroscopy will be used for sensitive in-situ monitoring of nanoparticle formation. We will also explore self-assembly of chiral nanoparticles and their incorporation into suitable matrices to produce novel composite materials with controlled chirality and nanoscale architecture. Such materials are promising in advanced optical applications, e.g. metamaterials.  Materials with controlled chirality, surface functionality and selective optical responses are a natural choice for biosensors. They can be tailored to detect a very small number of target molecules, since nanoparticle properties are much more sensitive to surface changes compared to bulk materials. Chiral nanoparticles are advantageous for enantioselective catalysis, where the current thrust is to efficiently synthesize molecules similar to natural compounds. Accordingly, our research will be directed to produce nanocomposite materials for catalysts and sensors.