Abstract

ROMERO, María Concepción  and  MENDEZ-TOVAR, Marcela. Impedance Analysis for the Study of Biofilm Formation on Electrodes: An Overview. J. Mex. Chem. Soc [online]. 2023, vol.67, n.4, pp.547-565.  Epub Apr 26, 2024. ISSN 1870-249X.  https://doi.org/10.29356/jmcs.v67i4.2005.

The application of Electrochemical Impedance Spectroscopy (EIS) in biofilms studies has been long reported due to the great variety and diversity of applications that are involved in many fields, for instance, in Bioelectrochemical Systems (BES), drinking water distribution systems, electrochemical sensors, food industry, medical devices; among others. Microbial attachment and biofilm growth have been extensively investigated using EIS due to their non-destructive nature; however, several studies (using a three-electrode system) have described changes in the electrochemical parameters that model biofilm development. Therefore, this overview focused on the EIS data analysis by an electrical equivalent circuit (eec). The most representative studies on attachment, biofilm formation, Extracellular Polymeric Substances (EPS), and charge transfer phenomena were discussed. Consequently, the goals of this overview are:

Distinguish between the ways of studying biofilm growth (in-situ/ex-situ).

EIS data validation by Kramers Kronig relations.

The discussion of the electrical elements of eec.

Due to the heterogeneity of the reviewed information, the biofilms are divided into two groups: strong electroactive and another group: weak electroactive and non-electroactive biofilms. The importance of this manuscript is to present the biofilm-electrode interface by the electrical elements of various biofilms studied under different conditions, establish an overview of the working methods followed by different authors, and discuss the results obtained on diverse biofilms. Lastly, this overview might help as a general outlook for planning further research.

Keywords : Biofilm -electrode interface; electrochemical impedance spectroscopy; electric equivalent circuit; strong electroactive biofilms, weak electroactive biofilms.