Methacrylate Polymer Scaffolding Enhances the Stability of Suspended Lipid Bilayers for Ion Channel Recordings and Biosensor Development

Black lipid membranes (BLMs) provide a synthetic environment that facilitates measurement of ion channel activity in diverse analytical platforms. The limited electrical, mechanical and temporal stabilities of BLMs pose a significant challenge to development of highly stable measurement platforms. Here, ethylene glycol dimethacrylate (EGDMA) and butyl methacrylate (BMA) were partitioned into BLMs and photopolymerized to create a cross-linked polymer scaffold in the bilayer lamella that dramatically improved BLM stability. The commercially available methacrylate monomers provide a simple, low cost, and broadly accessible approach for preparing highly stabilized BLMs useful for ion channel-functionalized analytical platforms. When prepared on silane-modified glass microapertures, the resulting polymer scaffold-stabilized (PSS)-BLMs exhibited significantly improved lifetimes of 23 +/- 9 to 40 +/- 14 h and > 10-fold increase in mechanical stability, with breakdown potentials > 2000 mV attainable, depending on surface modification and polymer crosslink density. Additionally, the polymer scaffold exerted minimal perturbation to membrane electrical integrity as indicated by mean conductance measurements. When gramicidin A and alpha-hemolysin were reconstituted into PSS-BLMs, the ion channels retained function comparable to conventional BLMs. This approach is a key advance in the formation of stabilized BLMs and should be amenable to a wide range of receptor and ion channel functionalized platforms.