Electrochemical Impedance Spectroscopy-Based Sensing of Biofilms: A Comprehensive Review

Abstract

Biofilms are complex communities of microorganisms that can form on various surfaces, including medical devices, industrial equipment, and natural environments. The presence of biofilms can lead to a range of problems, including infections, reduced efficiency and failure of equipment, biofouling or spoilage, and environmental damage. As a result, there is a growing need for tools to measure and monitor levels of biofilms in various biomedical, pharmaceutical, and food processing settings. In recent years, electrochemical impedance sensing has emerged as a promising approach for real-time, non-destructive, and rapid monitoring of biofilms. This article sheds light on electrochemical sensing for measuring biofilms, including its high sensitivity, non-destructive nature, versatility, low cost, and real-time monitoring capabilities. We also discussed some electrochemical sensing applications for studying biofilms in medical, environmental, and industrial settings. This article also presents future perspectives for research that would lead to the creation of reliable, quick, easy-to-use biosensors mounted on unmanned aerial vehicles (UAVs), and unmanned ground vehicles (UGVs), utilizing artificial intelligence-based terminologies to detect biofilms.

ZnO/Ag/Reduced Graphene Oxide Nanocomposite as a Conductive Layer for Electrochemical Monitoring of Candida albicans Biofilm Formation and Dynamics

“…However, electrochemical sensing systems, have emerged as highly successful tools for real-time monitoring of biofilms because of their ability to study various physical and electrical phenomenon happening at the interface such as changes in the capacitive behavior of the electrical double layer, variation in adsorption or desorption processes, or differences in the charge transfer reaction of an electrode, etc . Particularly, electrochemical impedance spectroscopy (EIS) has been preferred as a method for monitoring the dynamic behavior of biofilms due to its sensitivity and ability to capture time-dependent measurements of surface coverage followed by a change in the capacitive behavior of the electrode. , Conversely, cyclic voltammetry (CV) offers a rapid and straightforward approach for qualitative and quantitative analysis of biological and redox reactions, facilitating insights into the morphology of the electrode surface, as well as kinetics, thermodynamics, and the interplay of chemical processes. , Owing to the complexity of biofilms, a single analytical technique is in general insufficient to characterize it holistically. In addition to that, determining biofilm dynamics in the presence of external agents is also important to verify their antimicrobial efficacy. , Thus, the main objective of this study was to develop a nanomaterial that besides being inhibitory toward C. albicans biofilm could also facilitate the electrochemical monitoring of the degradation process.…”

“…31 Particularly, electrochemical impedance spectroscopy (EIS) has been preferred as a method for monitoring the dynamic behavior of biofilms due to its sensitivity and ability to capture time-dependent measurements of surface coverage followed by a change in the capacitive behavior of the electrode. 32,33 Conversely, cyclic voltammetry (CV) offers a rapid and straightforward approach for qualitative and quantitative analysis of biological and redox reactions, facilitating insights into the morphology of the electrode surface, as well as kinetics, thermodynamics, and the interplay of chemical processes. 34,35 Owing to the complexity of biofilms, a single analytical technique is in general insufficient to characterize it holistically.…”

Electrochemical Impedance Spectroscopy for Ion Sensors with Interdigitated Electrodes: Capacitance Calculations, Equivalent Circuit Models and Design Optimizations

“…Their high aspect ratio due to the comb-like electrode structure increases their sensing surface area and leads to higher sensitivity and high signal-to-noise ratio (SNR) [7,11]. Due to its benefits of low power consumption, high sensitivity, low limit of detection, wide linear response range, simple miniaturization, and the possibility to function without a reference electrode, EIS can enable many new applications, where portability is an important requirement [5,8,15]. Therefore, there is an increasing interest in its application in sensing.…”

“…Non-faradaic EIS does not involve redox reactions and is a non-destructive method compared to faradaic EIS. Thus, repeated measurements in the same sample are possible, and the sensor degradation over time is decreased [15]. Opposite to faradaic EIS, this method works without diffusion processes.…”

“…In this article, we focus on non-faradaic and label-free impedimetric sensors. Additionally, we are only considering two-electrode transducer models where no reference electrode is required due to their advantages of simple miniaturization, lower costs, and less drift [5,7,15]. Despite all the positive characteristics of EIS, it is a time-consuming method, as measurements over a wide frequency range are performed.…”