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Membrane proteins play essential roles in the cell, and they constitute one of the most important targets of drugs. Studying membrane proteins in a controlled model membrane environment can provide unambiguous, quantitative information on their molecular properties and functions. However, reconstituting membrane proteins in a model system poses formidable technological challenges. Here, we developed a novel model membrane platform for highly sensitive observation of membrane proteins by combining a micropatterned lipid membrane and a nanofluidic channel. A micropatterned model membrane was generated by lithographically integrating a polymerized lipid bilayer and a natural (fluid) lipid bilayer. A nanofluidic channel having a defined thickness was formed between the fluid bilayer and a polydimethylsiloxane (PDMS) slab by attaching the polymeric bilayer and PDMS slab using an adhesion layer composed of silica nanoparticles that are coated with a biocompatible polymer brush. As we reconstituted rhodopsin (Rh), a G-protein-coupled receptor (GPCR), from a detergent-solubilized state into the fluid bilayer, only successfully reconstituted Rh molecules diffused laterally in the lipid bilayer and migrated into the nanogap junction, where they could be observed with a vastly improved signal-to-background ratio. The nanogap junction effectively separates the sites of reconstitution and observation and provides a novel platform for studying the molecular properties and functions of membrane proteins at the single-molecular level.

Disubstituted adamantanes having pyrogallol derivatives as V-shaped host molecules were synthesized to prepare complexes with carboranes, which are representative spherical guest molecules for macrocyclic compounds, including calixarenes and cyclotriveratrylenes. The crystallization of o-carborane (a) and 1,3-bis(3,4,5-trimethoxyphenyl)adamantane (1) in toluene resulted in the formation of inclusion crystals (1a) in a 1 : 1 ratio. X-ray crystallographic analysis revealed that two oxygen atoms in 1 interact with two hydrogen atoms of a through CH⋯O interactions to afford the complexes. In the case of 1,3-bis(3,4,5-triethoxyphenyl)adamantane (2), no inclusion crystal was obtained due to steric hindrance of the ethyl groups. Furthermore, the crystallization of 1 and a benzoquinone derivative (b) provided reddish crystals (1b) with a 1 : 2 host : guest complexation stoichiometry, where lone pair⋯π interactions in the complexes were observed in addition to donor–acceptor interactions.