Dominant parameters and informational content of VIEC time constants

Determine the dominant geometric and transport parameters that influence the time constants of current transients in vesicle impact electrochemical cytometry (VIEC), and identify what information these time constants provide regarding vesicle size and transport properties such as diffusion coefficients inside and outside the vesicle.

Background

The paper studies exocytosis-like events using vesicle impact electrochemical cytometry (VIEC), where vesicles rupture upon contacting a polarized ultramicroelectrode and release their contents, producing measurable current transients. Among various features of these transients, the authors focus on characterizing the decay time constant and its dependence on geometry (vesicle radius, pore dimensions, sensor distance) and transport properties (diffusion coefficients inside and outside the vesicle).

In motivating their work, the authors explicitly flag open questions regarding which parameters most strongly govern the observed time constants and what information can be inferred from them about vesicle size and transport. The remainder of the manuscript develops analytical and simulation-based scaling laws for these dependencies, aiming to address these questions.