Interface 1010t interface 1000

e-Bandage treatment was done with the agar membrane biofilm model. After 24 hours of growth, biofilms were transferred to a fresh TSA plate. One hundred microliters of hydrogel were placed on top of biofilm, and an e-bandage was placed on top of the hydrogel, with the WE side in contact with the biofilm. One hundred microliters of hydrogel were placed in between the cotton fabric layers of the e-bandage, where the reference electrode was situated, with a syringe needle. Finally, another 100 μl of hydrogel was placed on top of the e-bandage. A sterile Tegaderm^™ transparent film (3 M, ref #1622 W) was used to cover the e-bandage. e-Bandage wires were taped to the side of the TSA plate. Finally, the lid of the TSA plate was placed, and the TSA plates wrapped with parafilm. Each e-bandage was connected to a potentiostat (Interface 1010T/Interface 1000, Gamry) with a multiplexer (IMX8/ECM8, Gamry). The WE was polarized to −0.6 V_Ag/AgCl or 1.5 V_Ag/AgCl to generate H₂O₂ or HOCl, respectively, on the WE surface. For non-polarized (no production of oxidizing agents) conditions, the potentiostat was set to idle mode. Fig. 1A shows a schematic of the in vitro experimental setup with an e-bandage placed on top of a laboratory-grown biofilm on a polycarbonate membrane, and the potentiostat conditions for generation of HOCl or H₂O₂, or the non-polarized state.

Construction and preparation of the e-bandages was as previously described (28 (link)). e-Bandages were made of three electrodes: 1.77 cm² of carbon fabric (Panex 30 PW06, Zoltek Companies, Inc.) as the WE and CE, and an Ag/AgCl wire as the pseudo reference electrode. The electrodes are separated by cotton fabric and held together using silicon adhesive. 30 AWG titanium wires (TEMco, Amazon.com, cat#RW0517) were pressed with nylon sew-on snaps (Dritz, Spartanburg, SC, item#85) for electrical connectivity between the potentiostat cable (Interface 1010T/Interface 1000, Gamry) with a multiplexer (IMX8/ECM8, Gamry) and the WE and CE. The CE and WE were covered with hydrogel made from 1x PBS mixed with 1.8 % (w/v) xanthan gum (Namaste Foods, Amazon.com, UPC: 301155217160) to ensure electrochemical connectivity.