Role of Membrane Properties on Charge Transport Across Conjugated Oligoelectrolyte Modified Phospholipid Bilayers

Microorganisms have diverse metabolic pathways that enable them to convert hard to use energy sources (e.g., waste water) into useful products such as fuels, chemicals, and electrons for power generation. In many cases, bioelectrochemical systems have the potential to monitor, control, and enhance this metabolism for bio-processing, bio-reformation of fuels, and waste mitigation but slow microbe/electrode charge transfer has limited power densities and waste mitigation rates. Recent work has demonstrated that conjugated oligoelectrolyte (COE) additives enhance the microbial fuel cell power density and waste mitigation, but it remains poorly understood how additives like the COEs interact in phospholipid membranes. Here we examine how phospholipid membrane properties such as fluidity and charge alter COE incorporation and charge transport, using techniques including cyclic voltammetry and absorption spectroscopy. These properties are found to strongly influence COE behavior and can lead to large enhancements of both COE incorporation and activity.