Direct comparison of AFM and SEM measurements on the same set of nanoparticles

Abstract

This article is the first step in the development of a hybrid metrology combining AFM and SEM techniques for measuring the dimensions of a nanoparticle population in 3D space (X,Y,Z). This method exploits the strengths of each technique on the same set of nanoparticles. AFM is used for measuring the nanoparticle height and the measurements along X and Y axes are deduced from SEM images. A sampling method is proposed in order to obtain the best deposition conditions of SiO2 and gold nanoparticles on mica or silicon substrates. Only the isolated nanoparticles are taken into account in the histogram of size distribution. Moreover, a semi-automatic Matlab routine has also been developed to process the AFM and SEM images, measure and count the nanoparticles. This routine allows the user to exclusively select the isolated nanoparticles through a control interface. The measurements have been performed on spherical-like nanoparticles to test the method by comparing the results obtained with both techniques.

Volume determination of irregularly-shaped quasi-spherical nanoparticles

“…15 in Ref. (3). We extracted the pairs of SEM- and AFM-measured diameters for each Au NP, calculated their Dxyzs, and tabulated the results in Electronic Supplementary Material Table S3 for the reported 68 NPs.…”

“…(3), which stems from the fact that no accurate edge detection method has been developed for SEM images of Au nanoparticles. Due to this uncertainty, the reported diameters of Au NPs were extracted at the full-width-half-max of the SEM intensity profiles (3). This selection is a convenience based on the general nature of SEM imaging, but is not based on a rigorous model for imaging of Au NPs.…”

“…Nanomaterials in the form of nanoparticles (NPs) represent an important part of nanotechnology. NP usage is increasing at a rapid pace with the development of new types of nanomaterials, as indicated by the existence of over 1,300 diverse listed consumer goods (3) (e.g., sunscreen, cosmetics, clothes, food, drugs, paints, varnishes, and a self-cleaning coating for floors, walls and windows) in addition to medical (4) and high technology (5) applications. Reports indicate that nanotechnology and the use of NPs has the potential to radically change the way cancer is treated (6).…”

“…At present, apart from the electron tomography, it is nearly impossible to accurately determine the size of many types of NPs (including types of IS-NPs (1, 3)). For this reason, only reference materials (a less rigorous measurement certification process) exist for IS-NPs, such as gold (29, 30).…”

Combined influence of oxygenation and salinity on aggregation kinetics of the silver reference nanomaterial NM‐300K

“…This method of sample preparation by spin-coating was developed by the Laboratoire National de M etrologie et d'Essais (France) to obtain a good dispersion of NPs on the substrate (Delvall ee et al 2015). For this purpose, NM-300K NPs were deposited onto a silicon wafer by using a spin-coater.…”