Tethered membranes have been proven during recent years to be a powerful and flexible biomimetic platform. We reported in a previous article on the design of a new architecture based on the self-assembly of a thiolipid on ultrasmooth gold substrates, which shows extremely good electrical sealing properties as well as functionality of a bilayer membrane. Here, we describe the synthesis of lipids for a more modular design and the adaptation of the linker part to silane chemistry. We were able to form a functional tethered bilayer lipid membrane with good electrical sealing properties covering a silicon oxide surface. We demonstrate the functional incorporation of the ion carrier valinomycin and of the ion channel gramicidin.

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This paper presents a preparation route which allows the formation of a poly(phenylene) ionomer containing merely sulfone units (-SO 2 -) connecting the phenyl rings and in which each phenyl ring is monosulfonated (100% degree of sulfonation). This corresponds to an ion exchange capacity (IEC) of 4.5 mequiv g -1 (equivalent weight of EW ) 220 g equiv -1 ). The preparation succeeded in a two-step process comprising a polycondensation reaction of sulfonated difluorodiphenyl sulfone with sodium sulfide, yielding sulfonated poly(phenylene sulfide sulfone), and the subsequent oxidation to the corresponding sulfonated poly(phenylene sulfone). The polymer was characterized by elemental analysis, NMR, IR, GPC, viscosity measurement, TGA in air and in pure water vapor atmosphere, DSC at low and high temperatures, and ac impedance spectroscopy. Room temperature water absorption isotherms have been determined by equilibrating samples at different relative humidities. Under the chosen reaction conditions, polymers with molecular weights up to M w ≈ 61 000 g mol -1 were obtained, corresponding to intrinsic viscosities up to 0.73 dL g -1 . The water-soluble ionomer exhibits a very high density (F ) 1.75 g cm -3 in the dry form), no glass transition or melting temperature, and a very high thermooxidative and hydrothermal stability. The latter is attributed to the specific molecular structure consisting of extremely electron-deficient aromatic rings. At high temperature (T ) 110-160 °C) and low relative humidities (rh ) 50-15%) the proton conductivity exceeds that of Nafion by a factor of 5-7.

Tethered bilayer lipid membranes (tBLMs) are promising model architectures that mimic the structure and function of natural biomembranes. They provide a fluid, stable, and electrically sealing platform for the study of membrane related processes, specifically, the function of incorporated membrane proteins. This paper presents a generic approach toward the synthesis of functional tBLMs adapted for application to various surfaces. The central element of a tethered membrane consists of a lipid bilayer. Its proximal layer is covalently attached via a spacer unit to a solid support, either gold or silicon oxide. The membranes are characterized optically by using surface plasmon resonance spectroscopy (SPR) or ellipsometry and electrically by using electrochemical impedance spectroscopy (EIS). The bilayer membranes obtained show high electrical barrier properties and can be used to incorporate and study small membrane proteins in a functional form.