Preparation of a colored conductive paint electrode for electrochemical inactivation of bacteria

In this study we describe the preparation of a colored conductive paint electrode containing In₂O₃, SnO₂, or TiO₂ for the electrochemical inactivation of marine bacteria. When each colored conductive paint electrode was immersed in seawater containing 10⁶ cells/mL for 90 min, marine microbe attachment to the TiO₂/SnO₂/Sb electrode surface was minimal. Preparation of electrodes coated with 40% particles is shown to be more cost-effective, and because of their more translucent coatings they can be painted over with bright colors. When a potential of 1.0 V was applied for 30 min to the colored conductive paint electrode (40 wt% TiO₂/SnO₂/Sb) in sterile seawater, the survival ratio decreased to 55%. When 1.5 V vs. saturated calomel electrode (SCE) was applied, all attached cells were inactivated. Chlorine was not detected below an applied potential of 1.5 V. A change in pH was not observed in the range of 0 to 1.5 V. This method might be effective for preventing bacterial cell accumulation and the formation of biofilms.