Monitoring the cargo released was accomplished by vesicle impact electrochemical cytometry to detect DA or 5-HT stored in liposomes. A 33-μm carbon fiber electrode was placed in a liposome suspension as shown in Figure of the main text. Liposomes adsorbed on the microelectrode and ruptured via electroporation, the proposed mechanism for vesicle opening in the VIEC. The electrochemical recording of release of individual liposome content was performed by applying a constant positive potential (700 mV vs. Ag/AgCl) to the carbon fiber microelectrode in the form of spikes (a plot of current versus time). By analysis of each spike, important kinetic information about the release event can be obtained. Several parameters used for spike analysis in this work are depicted in the schematic in Figure of the main text including the width of spike at half maximum (thalf) as an indicator of duration of release events; the rise-time (trise), the time from 10% to 90% of amplitude on the rising part of each spike, which reflects fusion pore opening; the fall-time (tfall), the time from 90% to 10% of amplitude on the falling part of each spike that represents the time needed for chemical contents to exit the liposome, and the amplitude of spike (Imax) representing the maximum flux of molecules through the open pore. Additionally, the amount of monoamines (N) released from a single liposome was evaluated with Faraday's law: N=Q/zeF, where Q is the charge calculated by integrating current of each amperometric spike, ze is the number of electrons transferred during the redox reaction (2 for DA or 5-HT) and F is Faraday's constant (96 485 C•mol -1 ).