Alkyne-linked 2,2-disubstituted-indolin-3-one oligomers as extended beta-strand mimetics.

The design, synthesis, and structural analysis of a new foldamer that mimics an extended beta-sheet are presented. The nonpeptidic mimetic is based on a series of 2,2-disubstituted-indolin-3-one groups linked through their 4,7-positions by an alkyne spacer. An intramolecular hydrogen bond between the carbonyl of one indolinone subunit and the proximal NH of another subunit imposes a conformation that mimics the side chain positioning on a beta-strand.

Label-free immunodetection with CMOS-compatible semiconducting nanowires.

Semiconducting nanowires have the potential to function as highly sensitive and selective sensors for the label-free detection of low concentrations of pathogenic microorganisms. Successful solution-phase nanowire sensing has been demonstrated for ions, small molecules, proteins, DNA and viruses; however, 'bottom-up' nanowires (or similarly configured carbon nanotubes) used for these demonstrations require hybrid fabrication schemes, which result in severe integration issues that have hindered widespread application. Alternative 'top-down' fabrication methods of nanowire-like devices produce disappointing performance because of process-induced material and device degradation.