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

Abstract

Candida albicans, a pathogenic fungus, poses a significant threat, particularly in individuals with compromised immune systems, leading to elevated mortality rates. The problem is exacerbated by their ability to form biofilms on medical devices, such as catheters, thereby resisting treatments. To tackle this challenge, we have developed an innovative approach involving the detection and combatting of C. albicans biofilm and its associated stages in the presence of a unique antimicrobial nanocomposite (ZnO/Ag/RGO) coating. Microscopic assessments reveal the nanocomposite’s exceptional inhibitory impact on C. albicans cells, demonstrating its efficacy. Time-kinetic experiments further elucidate the restraining effects of ZnO/Ag/RGO coatings on C. albicans biofilm formation over intervals. The absence of hypha structures on nanocomposite-coated surfaces was also noted. A concentration-dependent decrease in cell adhesion further validates the potency of the nanocomposite. To substantiate our findings, we employed advanced techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltage spectrometry (CV) for real-time electronic monitoring of biofilm dynamics. These experiments revealed differences in the time- and concentration-dependent curves. While the concentration-dependent curve maintained linearity, the time-dependent graph portrayed a distinct expression, probably due to cell association. This work stands out as one of the few endeavors seeking to map events within the biofilm matrix in response to an external agent, providing valuable insights into the interplay between ZnO, Ag, and RGO and biofilm dynamics. Our present approach, combining microscopy and electrochemical data, holds promise in contributing to the development of sensing strategies for microbial biofilms and their inhibition.