Microelectrodes in Biological Systems

Wightman, R. Mark; Kennedy, Robert T.; Wiedemann, Donna J.; Kawagoe, Kirk T.; Zimmerman, Jayne B.

doi:10.1007/978-94-011-3210-7_27

Cited by 4 publications

(10 citation statements)

References 18 publications

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“…Inside neurons, neurotransmitters are sequestered in vesicles that upon stimulation are fused with the plasma membrane in a Ca 2+ -influx mediated process, resulting in the release of the vesicular contents into the extracellular environment. Electrochemical investigations have demonstrated that neurotransmitters are 5 released as small packages upon fusion of one vesicle at a time, 20 known as quantal release. Typically, micromanipulated carbon fiber microelectrodes (CFMEs) have been applied in electrochemical detection of released dopamine from single cells.…”

Section: -12mentioning

confidence: 99%

“…Typically, micromanipulated carbon fiber microelectrodes (CFMEs) have been applied in electrochemical detection of released dopamine from single cells. 20 However, during recent years, metal electrode systems 10 based on lithographic microsensor technology have gained increasing attention. 21 Aside from suitability for single cell detection, microfabricated metal electrodes have the advantage of facilitating monitoring of dopamine release from populations of adherently growing cells.…”

Section: -12mentioning

confidence: 99%

“…This approach gives possibility for fast 15 statistically significant screening of cell populations with respect to their dopaminergic properties. It can effectively answer biologically relevant questions in the field of neural stem cell research where the ability of chosen differentiation conditions need to be evaluated in terms of an increase in the number of 20 dopaminergic neurons in a cell population. 22,23 Dopamine detection at a bare metal electrode surface can be hampered by electrode fouling due to polymerization of dopamine on the electrode surface 24 during electrooxidation and by the presence of negatively charged interferents, such as 25 ascorbate.…”

Section: -12mentioning

confidence: 99%

“…35 Incorporating an anion in the polymer 3-). Evaluation of the obtained peak currents immediately leads to the conclusion that an electrode modified with a PPy film 20 electropolymerized using large counter ions as dopants, such as DS -or PSS -, yields a significantly higher response than those having small counter ions, such as Cl -, SO 4 2-and PO 4 3-(for a full comparison of all the counter ions used, see ESI †). In fact, an overoxidized PPy film doped with small counter ions has a 25 response similar to that of a non-doped overoxidized PPy film, indicating that the small counter ions do not enhance the signal response and, therefore, neither the sensitivity of the electrodes.…”

Section: Counter Ion Dopingmentioning

confidence: 99%

“…In detection of single vesicle exocytotic 15 events, various parameters can be extracted from recorded current-time traces (spikes), such as the integrated area of the current spikes (the charge Q yielding the amount of molecules released during each event), the maximum oxidation current, half-width t ½ , and the rise-time. 45 In measurements of dopamine 20 release from a cell population, the recorded current-time traces are composed of a large number of superimposed single vesicle events. In this case, the most significant parameter is the total charge, which, in an analogous manner as in the case of single vesicle measurements, is proportional to the detected amount.…”

Section: Exocytosis Measurementsmentioning

confidence: 99%

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Doped overoxidized polypyrrole microelectrodes as sensors for the detection of dopamine released from cell populations

Sasso

Heiskanen

Diazzi

et al. 2013

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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 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 polystyrene sulfonate anion (PSS-). 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 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

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Section: -12mentioning

confidence: 99%

Section: -12mentioning

confidence: 99%

Section: -12mentioning

confidence: 99%

Section: Counter Ion Dopingmentioning

confidence: 99%

Section: Exocytosis Measurementsmentioning

confidence: 99%

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Doped overoxidized polypyrrole microelectrodes as sensors for the detection of dopamine released from cell populations

Sasso

Heiskanen

Diazzi

et al. 2013

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Characterization of the effects of varying the pH and monomer concentrations of poly(oxyphenylene) insulating films on carbon fiber electrodes

MacTaylor¹,

Ewing²

1997

Electroanalysis

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By varying the conditions of an electrodeposition solution containing phenol and 2-allylphenol, thin poly(oxypheny1ene) films can be formed. These films have been used to insulate flame-etched carbon fiber electrodes to produce smaller electrode tip diameters. Experiments have been performed to test both the insulating properties and the film thickness of this poly(oxypheny1ene) copolymer at pH 5.0,7.0, and 9.0. The effects of monomer concentration on the polymer insulation integrity and film thickness have also been investigated. These experiments show that a decrease in pH results in thinner insulating films. It is also shown that monomer concentration can be decreased to 12mM phenoV18mM 2-allylphenol without causing an appreciable change in the insulating properties of the copolymer film; however, as the concentration is decreased, the pH appears to have less influence on the copolymer thickness.

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Signaling pathways involved in Ca2+- and Pb2+-induced vesicular catecholamine release from rat PC12 cells

et al. 2002

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2121 21 21Since Pb substitutes for Ca in essential steps leading to exocytosis, we have investigated whether Ca and Pb induce exocytosis through similar pathways. Vesicular catecholamine release was measured from dexamethasone-differentiated PC12 cells using carbon fiber microelectrode amperometry. Effects of drugs known to modulate PKC (PMA, staurosporine), calcineurin (cyclosporin A), calmodulin (W7), and CaM kinase II (KN-62) activity were investigated in intact and in ionomycin-permeabilized PC12 cells. Activation

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Microelectrodes in Biological Systems

Cited by 4 publications

References 18 publications

Doped overoxidized polypyrrole microelectrodes as sensors for the detection of dopamine released from cell populations

Doped overoxidized polypyrrole microelectrodes as sensors for the detection of dopamine released from cell populations

Characterization of the effects of varying the pH and monomer concentrations of poly(oxyphenylene) insulating films on carbon fiber electrodes

Signaling pathways involved in Ca2+- and Pb2+-induced vesicular catecholamine release from rat PC12 cells

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