Feedback Control of Biomolecular Systems Formed From Droplet-Interface Bilayers Available to Purchase

Applying feedback control strategies to biological materials establishes a new paradigm for creating controlled biomolecular systems. Specifically, current tracking and feedback voltage amplification are demonstrated separately on bilayer lipid membranes (BLMs) formed via the droplet-interface bilayer (DIB) method. Ion channel induced degradation of the bilayer is studied in order to provide a convenient method for causing changes to the bilayer which can be monitored using proportional-integral (PI) feedback voltage control. Alpha-hemolysin (αHL) from Staphylococcus aureus was shown to cause large scale reductions (+90%) to the resistance of the lipid bilayers formed at the interface of connected water droplets within 90 minutes of bilayer formation. Feedback integral current control was demonstrated on pure 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) DIBs not containing αHL and provided accurate current tracking of a 100pA desired current signal driven at a rate of 10mHz and less. Voltage amplification monitoring was achieved on DPhPC DIBs containing αHL, providing a way to detect decreasing resistance and capacitance of the bilayer and nonlinear current-voltage relationship.