硫醇包裹的纳米金颗粒具有独特的光致发光特性，其中金核以及表面金原子-配体相互作用均影响其发光性质。最近的研究表明，对于粒径在2-3nm的发光纳米金，体系中起到关键作用的是颗粒表面与硫醇相互作用而形成的具有一定d轨道空穴的阳离子态金。但是，对于其中d轨道空穴数量与体系的发光性质之间，尚未有一个确切的联系。为了实现对纳米金发光性质的调控，我们需要了解纳米金体系中导致发光的阳离子态金的确切的电子结构。由于合金的形成可以产生原子间的电荷转换，我们将通过向纳米金体系中引入合金的方法对金的d轨道空穴进行调控。在本项目中，我们将选取几种贵金属和过渡金属，与纳米金形成合金颗粒，研究合金的形成对于纳米金发光的影响。利用X射线吸收精细结构，分析纳米合金颗粒的结构以及其中具有光学活性的金的电子态。结合荧光光谱所得的光学性质，我们将建立纳米金电子结构与光学性质的联系，实现对纳米金颗粒体系光致发光的调控。

Thiol-capped gold nanoparticles (AuNP) are found to exhibit unique luminescence properties. It has complex mechanism and is far from understood, since both metallic Au core and the thiolated Au surface might be responsible for the luminescence. It is recently proposed that for AuNP within the size of 2-3 nm, the luminescence is primarily originated from the cationic Au, in which Au loses some d electrons upon interacting with the thiol melecules. However, the solid, quantitative connection between the number of d holes in Au and the observed luminescence is still missing. In order to make the luminescence properties of Au nanoparticles tunable, we need to fully understand the electronic structure of cationic Au that is responsible for the luminescence. In our proposal, the d electrons in Au will be tuned by charge transfer upon the formation of bimetallic alloys. Selected noble metals and transition metals will be introduced to AuNP, and the influence of alloy formation on the luminescence will be investigated. The structure of the alloys and electronic states of optically active Au species will be studied using X-ray absorption fine structure. Combing with pholuminescence, the connection between Au electronic structure and its luminescence properties will be established.