Operando Investigation of the Synergistic Effect of Electric Field Treatment and Copper for Bacteria Inactivation

Abstract As the overuse of chemicals in our disinfection processes becomes an ever-growing concern, alternative approaches to reduce and replace the usage of chemicals is warranted. Electric field treatment (EFT) has shown promising potential to have synergistic effects with standard chemical-based methods as they both target the cell membrane specifically. In this study, a lab-on-a-chip device is used to understand, observe, and quantify the synergistic effect between EFT and Cu inactivation. Our results indicate the overall inactivation performance is amplified with increasing Cu concentrations and electric field strengths. The natural residual effect of Cu can also be advantaged with the addition of EFT, and a faster overall disinfection performance can be achieved. Observations in situ, and at a single cell level, ensure us that the combined approach has an enhancement effect leading more bacteria to be weakened by EFT and susceptible to inactivation by Cu ion permeation. To our knowledge, it is the first time that researchers have been able to visually conclude the synergistic effects of EFT-Cu, allowing us to open the door to a multitude of opportunities to further study and better understand how this technology can optimally develop, mature, and scale for its various applications in the future.