Rapid, 3D Chemical Profiling of Individual Atmospheric Aerosols with Stimulated Raman Scattering Microscopy

Abstract

Abstract Visualizing the 3D chemical profiles of individual aerosols is crucial to understand their formation and aging processes, yet remains technically challenging. Here, the first application of stimulated Raman scattering (SRS) microscopy on 3D chemical imaging of individual aerosols in a nondestructive manner is demonstrated. SRS is capable of mapping chemical components of aerosols at a speed four orders of magnitude faster than conventional spontaneous Raman microscopy. Spatially resolved distributions of nitrates and sulfates reveal the fine structures and different mixing states of atmospheric particles. Moreover, high‐throughput quantifications of chemical compositions and particle size distributions are realized by large‐area imaging and statistical analysis. Its high‐speed and 3D chemical quantification capabilities promise SRS microscopy as a unique tool for studying the properties of single atmospheric particles, and ultimately their impacts on climate and human health.