Journal article
Doped Overoxidized Polypyrrole Microelectrodes as Sensors for the Detection of Dopamine Released from Cell Populations
Nano Bio Integrated Systems, Department of Micro- and Nanotechnology, Technical University of Denmark1
Department of Micro- and Nanotechnology, Technical University of Denmark2
Bioanalytics, Department of Micro- and Nanotechnology, Technical University of Denmark3
Technical University of Denmark4
Polytechnic University of Milan5
University of Genoa6
A surface modification of interdigitated gold microelectrodes (IDEs) with a doped polypyrrole (PPy) film for detection of dopamine released from populations of differentiated PC12 cells is presented. A thin PPy layer was potentiostatically electropolymerized from an 10 aqueous pyrrole solution onto electrode surfaces.
The conducting polymer film was doped during electropolymerization by introducing counter ions in the monomer solution. Several counter ions were tested and the resulting electrode modifications were characterized electrochemically to find the optimal dopant that increases sensitivity in dopamine detection.
Overoxidation of the PPy films was shown to contribute to a significant enhancement in sensitivity to dopamine. The changes caused by overoxidation in the electrochemical behavior and electrode morphology were investigated using cyclic voltammetry and SEM as well as AFM, respectively. The optimal dopant for dopamine detection was found to be polystyrenesulfonate anion (PSS-15 ).
Rat pheochromocytoma (PC12) cells, a suitable model to study exocytotic dopamine release, were differentiated on IDEs functionalized with an overoxidized PSS--doped PPy film. The modified electrodes were used to amperometrically detect dopamine released by populations of cells upon triggering cellular exocytosis with an elevated K+ concentration.
A comparison between the generated current on bare gold electrodes and gold electrodes modified with overoxidized doped PPy illustrates the clear advantage of the modification, yielding 2.6-fold signal amplification. The results also 20 illustrate how to use cell population based dopamine exocytosis measurements to obtain biologically significant information that can be relevant in, for instance, the study of neural stem cell differentiation into dopaminergic neurons.
Language: | English |
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Publisher: | The Royal Society of Chemistry |
Year: | 2013 |
Pages: | 3651-3659 |
ISSN: | 13645528 and 00032654 |
Types: | Journal article |
DOI: | 10.1039/C3AN00085K |
ORCIDs: | Heiskanen, Arto , Dimaki, Maria , Castillo, Jaime , Svendsen, Winnie Edith and Emnéus, Jenny |