Department of Chemistry, Oxford University, UK.
Nanoscale. 2019 Jan 23;11(4):1720-1727. doi: 10.1039/c8nr09172b.
We show that the electrochemical particle-impact technique (or 'nano-impacts') complements light scattering techniques for sizing both mono- and poly-disperse nanoparticles. It is found that established techniques - Dynamic Light Scattering (DLS) and Nanoparticle Tracking Analysis (NTA) - can accurately measure the diameters of '30 nm' silver particles assuming spherical shapes, but are unable to accurately size a smaller '20 nm' sample. In contrast, nano-impacts have a high accuracy (<5% error in effective diameters) and are able to size both individual '20 nm' and '30 nm' silver NPs in terms of the number of constituent atoms. Further study of a '20 nm and 30 nm' bimodal sample shows that the electrochemical technique resolves the two very similar sizes well, demonstrating accurate sizing regardless of particle size polydispersity, whereas due to inherent limitations of light scattering measurements this is not possible for DLS and NTA. Electrochemical sizing is concluded to offer significant attractions over light scattering methods.
我们表明，电化学粒子撞击技术（或“纳米撞击”）补充了光散射技术，可用于测量单分散和多分散纳米颗粒的尺寸。研究发现，传统技术——动态光散射（DLS）和纳米颗粒跟踪分析（NTA）——可以在假设球形的情况下准确测量“30nm”银颗粒的直径，但无法准确测量较小的“20nm”样品。相比之下，纳米撞击具有高精度（有效直径误差<5%），能够根据组成原子的数量来测量单个“20nm”和“30nm”银 NPs 的尺寸。对“20nm 和 30nm”双峰样品的进一步研究表明，电化学技术可以很好地分辨这两种非常相似的尺寸，证明了无论颗粒尺寸多分散性如何，都可以进行准确的尺寸测量，而由于光散射测量的固有局限性，DLS 和 NTA 则无法做到这一点。电化学尺寸测量被认为比光散射方法具有显著的优势。
