Lithographic Microfabrication of a 16-Electrode Array on a Probe Tip for High Spatial Resolution Electrochemical Localization of Exocytosis
Journal article, 2016

We report the lithographic microfabrication of a movable thin film microelectrode array (MEA) probe consisting of 16 platinum band electrodes placed on top of a supporting borosilicate glass substrate. These 1.2 mu m wide electrodes were tightly packed and positioned parallel in two opposite rows within a 20 mu m x 25 mu m square area and with a distance less than 10 mu m from the edge of the glass substrate. We demonstrate the ability to control and place the probe in close proximity to the surface of adherent bovine chromaffin cells and to amperometrically record single exocytosis release events with high spatiotemporal resolution. The two-dimensional position of single exocytotic events occurring in the center gap area separating the two rows of MEA band electrodes and that were codetected by electrodes in both rows was determined by analysis of the fractional detection of catecholamine released between electrodes and exploiting random walk simulations. Hence, two-dimensional electrochemical imaging recording of exocytosis release between the electrodes within this area was achieved. Similarly, by modeling the current spikes codetected by parallel adjacent band electrodes positioned in the same electrode row, a one-dimensional imaging of exocytosis with submicrometer resolution was accomplished within the area. The one- and twodimensional electrochemical imaging using the MEA probe allowed for high spatial resolution of exocytosis activity and revealed heterogeneous release of catecholamine at the chromaffin cell surface.

Author

Joakim Wigström

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

Johan Dunevall

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

Neda Najafinobar

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

Jelena Lovric

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

Jun Wang

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

Andrew Ewing

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

Ann-Sofie Cans

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

Analytical Chemistry

0003-2700 (ISSN) 1520-6882 (eISSN)

Vol. 88 4 2080-2087

Subject Categories

Inorganic Chemistry

Analytical Chemistry

DOI

10.1021/acs.analchem.5b03316

PubMed

26771211

More information

Created

10/7/2017