Membrane channel proteins play crucial roles in governing the transport of material and energy across every cellular membrane. Accordingly, they are the subjects of interest for science, medicine, and engineering as well as major targets of drug discovery efforts. Recent work has also shown their potential as highly rapid and sensitive single molecule sensors. However, techniques conventionally used to create the freestanding lipid membranes to measure the electrical transport through these proteins have shortcomings. These two-dimensional membranes, 5nm thick and up to hundreds of um in width, can be problematic to form and are extremely fragile, limiting the range and scope of possible studies. We have developed two new technologies which have addressed these problems: in situ encapsulation of lipid membranes in hydrogels and automated microfluidic formation. The hydrogel encapsulated membranes are encased within a hydrogel which molds to it on almost molecular length scales. As a result, they are mechanically robust and long-lived as a result of the intimate contact between the hydrogel and the membrane, enabling measurements of single channel currents for a week or longer. Our preliminary work has also shown that this gel slows the translocation of single-stranded DNA through the incorporated protein, possibly reducing the required measurement bandwidths sufficiently to enable sequencing. The automated microfluidic formation apparatus enables the creation and manipulation of lipid membranes and the incorporation and measurement of channel proteins in these membranes through a novel two phase fluid extraction. This device geometry is particularly amenable to scaling and automation. I will report our initial development and results of these technologies as well as progress toward exploiting them to DNA sequencing, drug discovery, and single molecule experiments.
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