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According to the Centers of Disease Control and Prevention, antibiotics decrease in effectiveness as bacteria gain resistance for previously treatable illnesses. Currently, antibiotic susceptibility is typically carried out via the Kirby-Bauer method. Even with automation, this process requires two incubation periods so a less time-consuming technique is desirable. Single entity electrochemistry (SEE) detects changes in current when collisions of individual particles at an ultramicroelectrode (UME) are linked with an electrochemical event. Our group has obtained step-like and spike-like responses of Saccharomyces cerevisiae at the UME surface as a result of adsorption and desorption, respectively. This response is due to the blocking of redox molecules from reaching UME surface and therefore related to several factors including particle geometry. We have used COMSOL software to model blocking events of a stationary particle on the UME. The cell was considered as a sphere to block diffusive flux of redox molecules with magnitude dependent upon location on the XY plane. Future work includes investigating conditions to select for adsorption so that electrochemical communication of cells may be observed using a two-mediator system for probing redox sites extra- and intracellularly. Upon completion of these studies, insights may be gained into collisional dynamics of cells at UMEs as well as real-time monitoring of cell metabolism using SEE.

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saccharomyces cerevisiae, single entity electrochemistry, potassium ferrocyanide, ultramicroelectrode


Analytical Chemistry | Cell Biology | Physical Chemistry

Faculty Advisor/Mentor

Julio C Alvarez

Is Part Of

VCU Graduate Research Posters

Activity of Saccharomyces cerevisiae by Single Entity Electrochemistry