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As a prerequisite to the development of real label-free bioassay applications, a high-throughput top–down nanofabrication process is carried out with a combination of nanoimprint lithography, anisotropic wet-etching, and photolithography methods realizing nanoISFET arrays that are then analyzed for identical sensor characteristics. Here, a newly designed array-based sensor chip exhibits 32 high aspect ratio silicon nanowires (SiNWs) laid out in parallel with 8 unit groups that are connected to a very highly doped, Π-shaped common source and individual drain contacts. Intricately designed contact lines exert equal feed-line resistances and capacitances to homogenize the sensor response as well as to minimize parasitic transport effects and to render easy integration of a fluidic layer on top. The scalable nanofabrication process as outlined in this article casts out a total of 2496 nanowires (NWs) on a 4 inch p-type silicon-on-insulator (SOI) wafer, yielding 78 sensor chips based on nanoISFET arrays. The sensor platform exhibiting high-performance transistor characteristics in buffer solutions is thoroughly characterized using state-of-the-art surface and electrical measurement techniques. Deploying a pH sensor in liquid buffers after high-quality gas-phase silanization, nanoISEFT arrays demonstrate typical pH sensor behavior with sensitivity as high as 43 ± 3 mV·pH–1 and a device-to-device variation of 7% at the wafer scale. Demonstration of a high-density sensor platform with uniform characteristics such as nanoISFET arrays of silicon (Si) in a routine and refined nanofabrication process may serve as an ideal solution deployable for real assay-based applications.

Structure Structure D 2000Self-Assembly in Aqueous Solution of Wheel-Shaped Mo 154 Oxide Clusters into Vesicles. -As revealed by light-scattering data and TEM, wheel-shaped Mo 154 oxide clusters self-assemble in aqueous solution into vesicles, hollow spherical structures with an average, almost monodisperse radius of about 45 nm and composed of approximately 1165 {Mo154} clusters. Unlike conventional lipid vesicles, the structures are not stabilized by hydrophobic interactions. It is suggested that the formation of the polyoxomolybdate-based vesicles is caused by a subtle interplay between short-range van der Waals attraction and long-range electrostatic repulsion, with important further stabilization arising from hydrogen bonding involving H2O molecules encapsulated between the wheel-shaped clusters and in the vesicles' interior. -(LIU, T.; DIEMANN, E.; LI, H.; DRESS, A. W. M.; MUELLER, A.; Nature (London, UK) 426 (2003) 6962, 59-62; Dep. Phys., Brookhaven Natl. Lab., Upton, NY 11973, USA; Eng.) -W. Pewestorf 05-007

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