All-(111) Surface Silicon Nanowires: Selective Functionalization for Biosensing Applications

M.N. Masood, S. Chen, Edwin Carlen, Albert van den Berg

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    e demonstrate the utilization of selective functionalization of carbon-silicon (C-Si) alkyl and alkenyl monolayers covalently linked to all-(111) surface silicon nanowire (Si-NW) biosensors. Terminal amine groups on the functional monolayer surfaces were used for conjugation of biotin n-hydroxysuccinimide ester. The selective functionalization is demonstrated by contact angle, x-ray photoelectron spectroscopy (XPS), and high resolution scanning electron microscopy (HRSEM) of 5-nm diameter thiolated Au nanoparticles linked with streptavidin and conjugated to the biotinylated all-(111) surface Si-NWs. Electrical measurements of monolayer passivated Si-NWs show improved device behavior and performance. Furthermore, an analytical model is presented to demonstrate the improvement in detection sensitivity of the alkyl and alkenyl passivated all-(111) Si-NW biosensors compared to conventional nanowire biosensor geometries and silicon dioxide passivation layers as well as interface design and electrical biasing guidelines for depletion-mode sensors.
    Original languageUndefined
    Pages (from-to)3422-3428
    Number of pages7
    JournalACS applied materials & interfaces
    Issue number12
    Publication statusPublished - Nov 2010


    • nanowires
    • biosensing
    • EWI-19443
    • IR-75859
    • Si-C monolayers
    • METIS-277511
    • Silicon

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