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Determining the Aggregation Kinetics of Nanoparticles by Single Nanoparticle Counting

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journal contribution
posted on 23.12.2020, 16:07 by Di Jiang, Hai-Bo Chen, Chen Qian, Xiao-Li Zhou, Xian-Wei Liu
The environmental behavior of nanoparticles in aquatic environments is highly dependent on the state of aggregation. Understanding the nanoparticle aggregation process is important for being able to predict nanoparticle transport and fate. However, direct observation of the initial aggregation process remains a challenge. Here, we demonstrated a plasmonic imaging technique that can measure the aggregation kinetics of nanoparticles at the single-particle level. This technique is based on the scattering of a surface plasmonic wave by a single nanoparticle and generates images sensitive to the particle size. Using this technique, we determined the aggregation attachment efficiency and the water chemistry conditions responsible for aggregation by imaging and counting single nanoparticles. Furthermore, we quantified the nanoparticles in each aggregate with data processing, providing insights into the aggregation dynamics at the microscopic level. These results demonstrated that nanoparticle aggregation kinetics can be probed with plasmonic single-particle imaging, and this technology can improve our understanding of particle–particle interactions and the fate of nanoparticles in an aquatic environment.