Branzi Lorenzo, Purcell-Milton Finn, Cressoni Chiara, Back Michele, Cattaruzza Elti, Speghini Adolfo, Gun'ko Yurii K, Benedetti Alvise
Department of Molecular Science and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, Venezia Mestre, Italy.
School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin 2, Ireland.
Nanoscale. 2022 Aug 25;14(33):12174-12182. doi: 10.1039/d2nr03330e.
Chiral semiconductor quantum dots have recently received broad attention due to their promising application in several fields such as sensing and photonics. The extensive work in the last few years was focused on the observation of the chiroptical properties in binary Cd based systems. Herein, we report on the first evidence of ligand-induced chirality in silver indium sulfide semiconductor quantum dots. Ternary disulfide quantum dots are of great interest due to their remarkable optical properties and low toxicity. Non-stoichiometric silver indium sulfide quantum dots were produced a room temperature coprecipitation in water, in the presence of cysteine as a capping agent. The obtained nanocrystals show a notable photoluminescence quantum yield of 0.24 in water dispersions. Several critical aspects of the nanocrystal growth and chemico-physical characterization, and the optimisation of the surface passivation by the chiral ligand in order to optimize the nanoparticle chirality are thoroughly investigated. Optical spectroscopy methods such as circular dichroism and luminescence as well as nuclear magnetic resonance techniques are exploited to analyze the coordination processes leading to the formation of the ligand-nanocrystal chiral interface. This study highlights the dynamic nature of the interaction between the nanocrystal surface and the chiral ligand and clarifies some fundamental aspects for the transfer and optimization of the chiroptical properties.
手性半导体量子点因其在传感和光子学等多个领域的应用前景，近年来受到了广泛关注。过去几年的大量工作集中在二元镉基体系中手性光学性质的观测上。在此，我们报道了硫化银铟半导体量子点中配体诱导手性的首个证据。三元二硫化物量子点因其卓越的光学性质和低毒性而备受关注。在水相中，以半胱氨酸作为封端剂，通过室温共沉淀法制备了非化学计量比的硫化银铟量子点。所获得的纳米晶体在水分散体系中显示出显著的光致发光量子产率，为0.24。我们对纳米晶体生长、化学物理表征的几个关键方面，以及通过手性配体优化表面钝化以优化纳米颗粒手性进行了深入研究。利用圆二色性和发光等光谱学方法以及核磁共振技术来分析导致配体 - 纳米晶体手性界面形成的配位过程。这项研究突出了纳米晶体表面与手性配体之间相互作用的动态性质，并阐明了手性光学性质转移和优化的一些基本方面。
