| 摘要 |
Chemical modification of a glass and fused silica nanopore surfaces results in surface properties that are ideal for localized bilayer formation over a nanopore and subsequent ion channel recording. With no surface modification, one may form a bilayer supported on the glass capillary extending across the nanopore orifice. Changing the surface properties from that of bare glass to a moderately hydrophobic surface produces a lipid monolayer above the glass and spontaneously yields a bilayer across the nanopore orifice, effectively corralling a single protein ion channel in the lipid bilayer region spanning nanopore orifice. The bilayer structure over the modified nanopore is such that current can only flow through the protein ion channel. The protein ion channel is able to diffuse in the bilayer above the pore opening, but cannot leave this area to enter the lipid monolayer. The bilayer formed across the nanopore orifice exhibits high electrical breakdown voltage, is stable to mechanical vibrations, and is long lived. Resistance through the protein channel can be measured electrically and is exploited for stochastic single-molecule detection. Protein ion channels can be inserted and removed from the bilayer by adjusting transmembrane pressure, and adapter molecules can be electrostatically trapped in the ion channel by applying high transmembrane voltages. |
