Synthesis and electrical characterization of bacterial biofilms

E.R. Cordeiro, H.P. de Oliveira, M.M. da Costa
Univasf, BR

Keywords: biofilms, bacteria, electrodes

Summary:

Biolfim formation is a complex and dinamic process, where bacteria collonies grow around a viscous material attached on a electrode surface. Under normal conditions, iron is typically insoluble and as a consequence it is found linked on the host proteins such as lactoferrin and transferring. In this work, we have explored the electrochemical properties of resulting films of Staphylococcus aureus applied as electrode of device immersed in aqueous solution of KCl (1M) as electrolyte. Cyclic voltammeter curves indicate a pair of peaks between -0.5V and 0.5V attributed to redox couple reactions while Nyquist plot of resulting films can be described in terms of two different regions: the diameter of semicircle at high frequency returns elevated value of faradic charge transfer resistance of the redox reactions while the linear branch at lower frequency is related with Warburg impedance. As we can see in the Fig. 2, vertical line at low frequency region represents the response of an ideal capacitor and introduces the possibility of charge transfer according Fick´s law. Based on previous analysis, we have explored the use of gram positive and gram negative bacteria on the production of biofilms applied as electrode of supercapacitors.