The functional properties of colloidal materials can be tailored by tuning the shape of their constituent particles. Unfortunately, a reliable, general methodology for purifying colloidal materials solely based on shape is still lacking. Here we exploit the single-particle analysis and sorting capabilities of the fluorescence-activated cell sorting (FACS) instrument, a commonly used tool in biomedical research, and demonstrate the ability to separate mixtures of synthetic microparticles based solely on their shape with high purity. We achieve this by simultaneously obtaining four independent optical scattering signals from the FACS instrument to create shape-specific ‘scattering signatures’ that can be used for particle classification and sorting. We demonstrate that these four-dimensional signatures can overcome the confounding effects of particle orientation on shape-based characterization. Using this strategy, robust discrimination of particles differing only slightly in shape and an efficient selection of desired shapes from mixtures comprising particles of diverse sizes and materials is demonstrated.

胶体材料的功能特性可以通过调整其组成颗粒的形状来定制。不幸的是，仍然缺乏可靠的，仅基于形状纯化胶体材料的通用方法。在这里，我们利用了荧光激活细胞分选（FACS）仪器（生物医学研究中常用的工具）的单颗粒分析和分选功能，并展示了仅基于其形状和高纯度即可分离合成微粒混合物的能力。我们通过同时从FACS仪器获得四个独立的光散射信号来创建特定形状的“散射特征”（可用于颗粒分类和分类）来实现这一目标。我们证明了这些四个维度的签名可以克服基于形状的表征上粒子定向的混杂影响。使用该策略，证明了对形状稍有不同的颗粒的鲁棒性判别，并从包含各种尺寸和材料的颗粒的混合物中有效选择了所需的形状。