On‐Chip Electrophoresis for Evaluating Zeta‐Potential of Nanoliposomes

The zeta=potential of nanoliposomes was evaluated using an electrophoretic mobility (EPM) measurement system that combines on-chip microcapillary electrophoresis with a low-noise EM-CCD camera. It enables the tracking electrophoretic migration of individual nanoliposomes (∼100 nm) and the accurate evaluation of the zeta-potential distribution of nanoliposomes. As a result, the size-dependent broadening of the EPM distribution of nanoliposomes due to the compositional fluctuation of a small number of lipid molecules was revealed for the first time. Assuming random compositional fluctuation, the standard deviation of EPM of nanoliposomes was calculated, so that the experimental data and theoretical data are well fitted.