Parameters affecting the accuracy of nanoparticle shape and size measurement in 3D.

While electron tomography can be used to visualize objects at nanoscale, it is difficult to perform reproducible quantitative measurements. Here we measure the shape and size of nanoparticles (NPs) in three dimensions (3D) using electron tomography. We evaluated the accuracy of maximum Feret diameter (Feretmax), minimum Feret diameter (Feretmini) and volume of NPs measurements from reconstructed 3D images which were obtained from data acquired with varied electron dose. We perform both simulations and experiment to clarify what factors effect on the accuracy of the NP shape measurement. Based on the results, suitable reconstruction methods and threshold for binarization were evaluated. We also report comparison results obtained on exactly the same samples in two different laboratories.