Resolving the size and charge of small particles: a predictive model of nanopore mechanics

The movement of small particles and molecules through membranes is widespread and has far-reaching implications. Consequently, the development of mathematical models is essential for understanding these processes on a micro level, leading to deeper insights. In this endeavour, we suggested a model based on a set of empirical equations to predict the transport of substances through a solid-state nanopore and the associated signals generated during their translocation. This model establishes analytical relationships between the ionic current and electrical double-layer potential observed during ana-lyte translocation and their size, charge, and mobility in an electrolyte solution. This framework allows for rapid interpretation and prediction of the nanopore system's behaviour and provides a means for quantitatively determining the physical properties of molecular analytes. To illustrate the analyt-ical capability of this model, ceria nanoparticles were investigated while undergoing oxidation or reduction within an original nanopore device. The re-sults obtained were found to be in good agreement with predictions from physicochemical methods. This developed approach and model possess transfer-able utility to various porous materials, thereby expediting research efforts in membrane characterization and the advancement of nano- and ultrafiltra-tion or electrodialysis technologies.