Electrospray-Scanning Mobility Particle Sizer (ES-SMPS)\nTechnique: Superior Sizing and Multimodal Characterization of Colloidal\nNanoparticles Compared to NTA and DLS

This\nstudy primarily employed three techniqueselectrospray-scanning\nmobility particle sizer (ES-SMPS), nanoparticle tracking analysis\n(NTA), and dynamic light scattering (DLS)to assess multimodal\nsamples. For monodisperse particles, both ES-SMPS (all sizes) and\nNTA (for particles larger than 40 nm) accurately determined the mean\nsize, while DLS overestimated it. The ES-SMPS technique demonstrated\nprecision in particle counting for multimodal samples, with a standard\ndeviation of around 2.5–4%. Conversely, NTA’s ability\nto count particles potentially leads to misinterpretation. The ES-SMPS\napproach could identify particle peaks in multimodal (bimodal, trimodal,\nand tetramodal) samples and show the relatively accurate position\nof the mode diameter. In contrast to ES-SMPS, DLS and NTA have weaknesses\nin characterizing multimodal samples. While NTA’s performance\ndepends on the optical properties of particles and cannot measure\nsilica particles smaller than 30–40 nm, ES-SMPS is independent\nof light scattering and can handle particles as small as ∼13\nnm. The ES-SMPS also excelled in separating particle peaks of the\nbimodal sample with a size interval gap of 10 nm, whereas NTA needs\nat least 20–50 nm depending on the particle type. To sum up,\nthe ES-SMPS method performs better and provides more accurate measurements\nfor characterizing multimodal samples compared to NTA and DLS.