Impedance spectroscopy of yeast cells attached to gold electrodes

RUIZ, GABRIEL; FELICE, CARMELO JOSÉ

BIOELECTROCHEMISTRY

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2012 p. 1 - 10

1567-5394

In this paper, we used the impedance spectroscopy and gold electrodes to monitor the attachment of yeast cell to the electrodes. We analyzed the effect of this attachment on electrode-electrolyte interface impedance. The tripolar cell was designed to produce a uniform electric field distribution on the working electrode, and to minimize the counter electrode impedance. Moreover, we used small AC overpotential (10 mV) to ensure stay into the limits of linearity of electrode-electrolyte interface impedance. Our present study demonstrated changes in impedance measurements only due to bacterial attachment avoiding the effect of conductivity changes. The experiments showed that Cdl decreased from (25.6±0.1) mF/cm2 to (22.6±0.1) mF/cm2 due to the adhesion of yeast cells, while Rct (21.44±0.06) kW do not showed statistically significant changes. We suggest that this decrease is due to an asymmetrical redistribution of surface charges on both side of cell that can be modeled as a biologic capacity connected in series with the double layer capacity of the interface.