Vesicle impact electrochemical cytometry (VIEC) measurements were performed using amperometry at a carbon fiber microelectrode placed in a liposome suspension. The microelectrodes were prepared by aspirating a 33-μm carbon fiber into a glass capillary (o.d. 1.2 mm; i.d. 0.69 mm; no filament; Sutter Instrument Co., USA). A commercial micropipette puller (PE-21, Narishige, Japan) was used to heat and pull the capillary producing two carbon fiber-containing pipettes. A scalpel was used to cut the protruding carbon fiber close to the glass tip and it was then dipped into freshly made epoxy (EpoTek 301, Epoxy Technology, USA) for 3 min. The glued electrodes were cured at 100 °C overnight and subsequently cut at the glass junction. The electrodes were consequently polished at a 45° angle on a commercial micro grinder (EG-400, Narishige, Japan) and backfilled with 3 M KCl. Each electrode was then tested in a 0.1 mM solution of dopamine in phosphate-buffered saline (PBS; pH 7.4) by performing cyclic voltammetry. Only electrodes with proper I-E curves were used for experiments.