Electrochemical Signature of Escherichia coli on Nickel Micropillar Array Electrode for Early Biofilm Characterization

Abstract

Biofilms are sessile microbial communities living at interfaces, in which the extracellular matrix is responsible for the mechanical stability and adhesion to surfaces. Transition from planktonic to attached cells is a key step in the biofilm formation process. Monitoring of this transition is needed to prevent contamination of biomedical devices and mitigate microbially influenced corrosion. Under anoxic local conditions and in the presence of an exogenous redox mediator, biofilms can divert part of the electron flow associated with catabolism to electrodes maintained at a defined potential. Extracellular electron transfer (EET) follows upon the attachment of planktonic cells to the surface. Modification of the electrode increases bacterial attachment, thus allowing early bioelectrochemical detection of the biofilm. Here, we report a Ni electrode micropillar array to detect early attachment of Escherichia coli biofilm through mediated EET in potentiostat‐controlled electrochemical cells. The biofilm‐surface interaction is studied by using electrochemical impedance spectroscopy (EIS) at different potentials and temperatures over 24 h. The analysis of the EIS signature highlights the effect of temperature on mediated EET in biofilms. These results demonstrate that micropillared electrodes allow earlier biofilm detection than flat electrodes, which is relevant to biofilm sensing and investigation of microbially influenced corrosion in drinking water systems and biomedical devices.

Microbial Electrochemical Systems: Principles, Construction and Biosensing Applications

“…Particular interest is always given to CV, since this method provides information about the formation of biofilms and their electrochemical and electro-catalytic activities, extracted from the realtime recording of voltammograms [81]. CV was used to characterize the anaerobic growth of E. coli and its secreted mediators and evaluate their role in the functioning of the cell, after the formation of a biofilm on the surface of the platinized titanium mesh electrodes [82]. Moreover, the biofilm formation and microbial adherence to the electrode surface could On the other hand, electrochemically inactive biofilms could be integrated with electrode surfaces via extracellular electron receptors/transmitters, or electron mediators.…”

Impedimetric detection of Pseudomonas aeruginosa attachment on flexible ITO-coated polyethylene terephthalate substrates

“…The changes in impedance at the low frequency region of the EIS plots observed in the DFRT with two resistor-CPE circuits (Figure 3d) was chosen to represent the electrochemical 282 system, with one additional resistor in series to account for the resistance in the solution [55].…”

Understanding the physical and biological effects of ultrasound on Pseudomonas aeruginosa biofilms

“…For such studies, external redox mediators were often added to aid the EET. For example, addition of ferricyanide/ferrocyanide couple or HNQ to the electrolyte exhibited a change in the charge transfer characteristics at the E. coli coated electrode [215,241,242]. The aforementioned studies showed the competence of EIS to detect the adhesion of weakly electroactive bacteria at the electrode via changes in impedimetric parameters such as charge transfer resistance and double layer capacitance with or without redox probes.…”

“…Previously, supplementing Enterococcus faecalis biofilms with iron promoted the EET thereby, increasing the electroactivity [214]. Similarly, addition of quinone derivatives such as anthraquinone-2,6-disulfonic acid and 2-hydroxy-1,4-naphthoquinone (HNQ) to Shewanella putrefaciens and E. coli respectively enhanced the EET activity [204,215].…”

“…Since the DFRT analysis showed two distinct time constants, a Randles equivalent circuit with two resistor-CPE circuits (Figure 4.3b) was chosen to represent the electrochemical system, with one additional resistor in series to account for the resistance in the solution [215]. Here, charge transfer and diffusion related effects, (from here on known as interfacial resistance) at electrode-biofilm interface were combined to simplify the circuit and apply Hsu-Mansfeld equation [219,263].…”