Organic conducting polymers (CPs) allow electronic charge transport down their conjugated backbone, which is then modulated by ionic doping and de-doping of the polymer bulk. The low impedance, mechanical compliance, and improved biocompatibility of CPs yield many advantages in biological interfacing. When functionalized with a recognition element, CPs can transduce and amplify sensing of target analytes to establish biosensors for a variety of applications. Scientists have historically leveraged sensing elements naturally found in biology, such as antibodies and enzymes. Recognition elements found in cell membranes have not been as thoroughly explored, but also show immense potential for developing highly selective and sensitive devices. To apply transmembrane proteins and ionophores in biosensing, lipid bilayers must first be established on the CP to functionalize the sensing surface and reduce nonspecific activity. However, these supported lipid bilayers (SLBs) lack long-term stability, severely limiting their utility in biosensor design.

One method of overcoming stability challenges and optimizing bilayer versatility is to incorporate block copolymers designed to mimic the structure and properties of lipids. In this work, hybrid supported lipid bilayers (HSLBs) containing both phospholipids and block copolymers are generated for the first time using a solvent-assisted method. Specifically, these HSLBs made by an organic solvent-aqueous buffer exchange can be created on CPs like the high-performing, commercially available poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). These blended membranes of a range of lipid and block copolymer compositions are assessed for complete bilayer surface coverage using quartz crystal microbalance (QCM) and for bilayer fluidity using fluorescence recovery after photobleaching (FRAP). The electrical sealing of these bilayers can additionally be monitored using electrochemical impedance spectroscopy (EIS), defining the dynamic range of the sensors.  Finally, the biosensing capabilities of the hybrid lipid-polymer bilayers on PEDOT:PSS are evaluated by monitoring the activity of model membrane proteins such as the bacterial toxin alpha-hemolysin. These results mark an important step toward achieving bioelectronic sensors with highly selective mechanisms of detection derived from cell membranes to produce a new class of biosensors with unique translational promise.