Graduation Year

2014

Location

Atrium, Center for Natural Sciences, Illinois Wesleyan University

Start Date

20-4-2013 2:00 PM

End Date

20-4-2013 3:00 PM

Description

Using Scanning Electrochemical Microscopy (SECM) with electrode probes that make simultaneous current and impedance measurements is useful for analysis of biological substrates. The current and impedance measurements are both dependent upon the proximity to a surface.

Experiments with the single carbon fiber electrodes show that the impedance measurements are independent of the current and applied potential. In order to detect neurotransmitter release from a cell, the electrode must be positioned very close to the cell surface. Impedance-based positioning eliminates the need for addition of biologically toxic redox mediators to position the electrode. Furthermore, it was found that multiple carbon fiber electrodes are able to explore a larger surface area than the single carbon fiber electrodes; this is useful for larger biological substrates, such as isolated taste buds. The distance-dependent impedance signals from multiple fiber electrodes were also characterized. Topographical images of biological substrates are generated by moving the electrode over the surface of the cells while monitoring the distance-dependent impedance signal. Because the current and impedance measurements are independent of each other, it is possible to combine imaging and other electrochemical techniques using the same electrode.

Included in

Chemistry Commons

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Apr 20th, 2:00 PM Apr 20th, 3:00 PM

Development and Characterization of Multi-Functional Probes for use with Scanning Electrochemical Microscopy

Atrium, Center for Natural Sciences, Illinois Wesleyan University

Using Scanning Electrochemical Microscopy (SECM) with electrode probes that make simultaneous current and impedance measurements is useful for analysis of biological substrates. The current and impedance measurements are both dependent upon the proximity to a surface.

Experiments with the single carbon fiber electrodes show that the impedance measurements are independent of the current and applied potential. In order to detect neurotransmitter release from a cell, the electrode must be positioned very close to the cell surface. Impedance-based positioning eliminates the need for addition of biologically toxic redox mediators to position the electrode. Furthermore, it was found that multiple carbon fiber electrodes are able to explore a larger surface area than the single carbon fiber electrodes; this is useful for larger biological substrates, such as isolated taste buds. The distance-dependent impedance signals from multiple fiber electrodes were also characterized. Topographical images of biological substrates are generated by moving the electrode over the surface of the cells while monitoring the distance-dependent impedance signal. Because the current and impedance measurements are independent of each other, it is possible to combine imaging and other electrochemical techniques using the same electrode.