On the mechanism of electrochemical vesicle cytometry: chromaffin cell vesicles and liposomes
Journal article, 2016

The mechanism of mammalian vesicle rupture onto the surface of a polarized carbon fiber microelectrode during electrochemical vesicle cytometry is investigated. It appears that following adsorption to the surface of the polarized electrode, electroporation leads to the formation of a pore at the interface between a vesicle and the electrode and this is shown to be potential dependent. The chemical cargo is then released through this pore to be oxidized at the electrode surface. This makes it possible to quantify the contents as it restricts diffusion away from the electrode and coulometric oxidation takes place. Using a bottom up approach, lipid-only transmitter-loaded liposomes were used to mimic native vesicles and the rupture events occurred much faster in comparison with native vesicles. Liposomes with added peptide in the membrane result in rupture events with a lower duration than that of liposomes and faster in comparison to native vesicles. Diffusional models have been developed and suggest that the trend in pore size is dependent on soft nanoparticle size and diffusion of the content in the nanometer vesicle. In addition, it appears that proteins form a barrier for the membrane to reach the electrode and need to move out of the way to allow close contact and electroporation. The protein dense core in vesicles matrixes is also important in the dynamics of the events in that it significantly slows diffusion through the vesicle.

Author

Jelena Lovric

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Analytical Chemistry

Neda Najafinobar

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Analytical Chemistry

Johan Dunevall

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Analytical Chemistry

Soodabeh Majdi

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Analytical Chemistry

I. Svir

Processus d'Activation Selective Par Transfert d'Energie Uni-Electronique ou Radiatif

A. Oleinick

Processus d'Activation Selective Par Transfert d'Energie Uni-Electronique ou Radiatif

C. Amatore

Processus d'Activation Selective Par Transfert d'Energie Uni-Electronique ou Radiatif

Andrew Ewing

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry, Analytical Chemistry

Faraday Discussions

1359-6640 (ISSN) 1364-5498 (eISSN)

Vol. 193 65-79

Subject Categories

Analytical Chemistry

DOI

10.1039/c6fd00102e

More information

Created

10/8/2017