Scanning electrochemical microscopy and its potential for studying biofilms and antimicrobial coatings

Abstract

Biofilms are known to be well-organized microbial communities embedded in an extracellular polymeric matrix, which supplies bacterial protection against external stressors. Biofilms are widespread and diverse, and despite the considerable large number of publications and efforts reported regarding composition, structure and cell-to-cell communication within biofilms in the last decades, the mechanisms of biofilm formation, the interaction and communication between bacteria are still not fully understood. This knowledge is required to understand why biofilms form and how we can combat them or how we can take advantage of these sessile communities, e.g. in biofuel cells. Therefore, in situ and real-time monitoring of nutrients, metabolites and quorum sensing molecules is of high importance, which may help to fill that knowledge gap. This review focuses on the potential of scanning electrochemical microscopy (SECM) as a versatile method for in situ studies providing temporal and lateral resolution in order to elucidate cell-to-cell communication, microbial metabolism and antimicrobial impact, e.g. of antimicrobial coatings through the study of electrochemical active molecules. Given the complexity and diversity of biofilms, challenges and limitations will be also discussed.

Characterization of Inherently Chiral Electrosynthesized Oligomeric Films by Voltammetry and Scanning Electrochemical Microscopy (SECM)

“…Further knowledge of the chemical and electrochemical phenomena involved in such systems can be obtained by high spatial resolution electrochemical techniques, such as scanning electrochemical microscopy (SECM) [ 14 ]. SECM is a scanning probe technique based on the amperometric signal generated at a microelectrode [ 15 ] by a redox-active species in solution (redox mediator), which can perform quantitative local electrochemical experiments for studying heterogeneous and homogeneous reactions and for high-resolution imaging of the chemical reactivity and topography of various surfaces [ 14 , 15 , 16 , 17 ].…”

Operando Scanning Electrochemical Probe Microscopy during Electrocatalysis

“…Under this condition, the sample surface can be unbiased or polarized (WE2) simultaneously with the tip, ensuring that the operando condition is intrinsically achieved as the tip and surface are modulated independently. The analytical aspects of SECM, its versatility for nanoscale studies, applications in heterogeneous electron transfer, , and biological processes have been reviewed. , The operation of SECM modes depends on the electrochemical processes occurring at the tip and the sample surface. In the ensuing sections, the main SECM modes and hybrid techniques are described.…”

“…The analytical aspects of SECM, 83 its versatility for nanoscale studies, 84 applications in heterogeneous electron transfer, 23 , 26 and biological processes have been reviewed. 85 , 86 The operation of SECM modes depends on the electrochemical processes occurring at the tip and the sample surface. In the ensuing sections, the main SECM modes and hybrid techniques are described.…”

Nanoarchitectonics of Triboelectric Nanogenerator for Conversion of Abundant Mechanical Energy to Green Hydrogen

“…The scanning electrochemical microscopy (SECM) technique was employed for the noninvasive examination of the hydrogen and oxygen generation and topographic details with a high spatial resolution of the substrates. [49][50][51][52] To demonstrate a prototype concept, floor-tilesshaped supporting substrates were 3D-printed using polylactic acid (PLA) filament, which were assembled to form the CS-TENG for energy harvesting from toe-tapping. Upscaling such smart tiles can be placed at busy bus or train stations to harvest mechanical energy from human walking to green hydrogen fuel.…”