Eaton P, Quaresma P, Soares C, Neves C, de Almeida M P, Pereira E, West P
REQUIMTE - LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
REQUIMTE - LAQV, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal.
Ultramicroscopy. 2017 Nov;182:179-190. doi: 10.1016/j.ultramic.2017.07.001. Epub 2017 Jul 5.
Nanoparticles have properties that depend critically on their dimensions. There are a large number of methods that are commonly used to characterize these dimensions, but there is no clear consensus on which method is most appropriate for different types of nanoparticles. In this work four different characterization methods that are commonly applied to characterize the dimensions of nanoparticles either in solution or dried from solution are critically compared. Namely, transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic light scattering (DLS) are compared with one another. The accuracy and precision of the four methods applied nanoparticles of different sizes composed of three different core materials, namely gold, silica, and polystyrene are determined. The suitability of the techniques to discriminate different populations of these nanoparticles in mixtures are also studied. The results indicate that in general, scanning electron microscopy is suitable for large nanoparticles (above 50 nm in diameter), while AFM and TEM can also give accurate results with smaller nanoparticles. DLS reveals details about the particles' solution dynamics, but is inappropriate for polydisperse samples, or mixtures of differently sized samples. SEM was also found to be more suitable to metallic particles, compared to oxide-based and polymeric nanoparticles. The conclusions drawn from the data in this paper can help nanoparticle researchers choose the most appropriate technique to characterize the dimensions of nanoparticle samples.
纳米颗粒的性质与其尺寸密切相关。有大量常用方法可用于表征这些尺寸，但对于哪种方法最适用于不同类型的纳米颗粒，尚无明确的共识。在这项工作中，对四种常用于表征溶液中或从溶液中干燥后的纳米颗粒尺寸的不同表征方法进行了严格比较。具体而言，将透射电子显微镜（TEM）、扫描电子显微镜（SEM）、原子力显微镜（AFM）和动态光散射（DLS）相互比较。测定了这四种方法对由三种不同核心材料（即金、二氧化硅和聚苯乙烯）组成的不同尺寸纳米颗粒的准确性和精密度。还研究了这些技术区分混合物中不同纳米颗粒群体的适用性。结果表明，一般来说，扫描电子显微镜适用于大尺寸纳米颗粒（直径大于50纳米），而原子力显微镜和透射电子显微镜对较小尺寸的纳米颗粒也能给出准确结果。动态光散射揭示了颗粒在溶液中的动力学细节，但不适用于多分散样品或不同尺寸样品的混合物。与基于氧化物和聚合物的纳米颗粒相比，扫描电子显微镜也被发现更适用于金属颗粒。从本文数据得出的结论可以帮助纳米颗粒研究人员选择最合适的技术来表征纳米颗粒样品的尺寸。
