Modeling Elastic Pore Sensors for Quantitative Single Particle Sizing.

An empirically derived model of how the dimensions of an elastic size-tunable pore sensor change with applied membrane stretch is presented. Quantitative modeling of the pore dimensions, in conjugation with a simplified pore resistance model, enabled particle size and translocation velocity profiles to be calculated from the individual particle 'pulse' events, at any membrane stretch. Size analysis of a trimodal suspension, composed of monodisperse 220, 330 and 410 nm particles, gave rise to 3 distinguishable particle peaks with coefficient of variances below 8.2% and average size values within 2.5% of single modal dynamic light scattering measurements. Particle translocation velocity profiles, over the approximate 12 μm pore sensing zone, showed that particles entering the small pore were initially accelerated to velocities approaching 5,000 to 6,000 μm/s. They then rapidly decelerated due to the pore geometry affects on the forces driving particle translocation, being the electric field strength and fluid flow.