The occurrence of biological homochirality is attributed to symmetry-breaking mechanisms which are still debatable. Studies of symmetry breaking require tools for monitoring the population ratios of individual chiral nano-objects, such as molecules, polymers, or nanocrystals. Moreover, mapping their spatial distributions may elucidate on their symmetry-breaking mechanism. While luminescence is preferred for detecting single particle chirality due to its high signal-to-noise ratio, the typical low optical activity of chromophores limits its applicability. Here, we report on handedness determination of single chiral lanthanide-based luminescent nanocrystals with a total photon count of 2 × 10⁴. Due to the large emission dissymmetry, we could determine the handedness of individual particles using only a single circular polarization component of the emission spectrum, without polarization modulation. A machine learning algorithm, trained to several spectral line shape features, enabled us to determine and spatially map the handedness of individual nanocrystals with high accuracy and speed. This technique may become invaluable in studies of symmetry breaking in chiral materials.

中文翻译：

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在一个单一手性纳米晶惯用的测定通过圆偏振发光

生物学同手性的发生归因于仍然存在争议的对称性破坏机制。对称破坏的研究需要用于监测单个手性纳米物体（例如分子，聚合物或纳米晶体）的人口比例的工具。而且，绘制它们的空间分布图可以阐明它们的对称性破坏机制。尽管发光由于其高的信噪比而优选用于检测单粒子手性，但生色团的典型低光学活性限制了其适用性。在这里，我们报告了单手性镧系元素发光纳米晶体的总手性测定，其总光子数为2×10 ⁴。由于发射不对称性很大，我们可以仅使用发射光谱中的单个圆偏振分量来确定单个粒子的旋律，而无需偏振调制。经过训练的机器学习算法具有多种光谱线形特征，使我们能够以高精度和高速度确定并在空间上绘制单个纳米晶体的手性。该技术在手性材料对称性断裂研究中可能会变得无价。