AVS 53rd International Symposium
    MEMS and NEMS Monday Sessions
       Session MN+BI-MoA

Paper MN+BI-MoA3
Novel and Direct Functionalization of PECVD SiCN for Resonant NEMS Biosensor Applications

Monday, November 13, 2006, 2:40 pm, Room 2007

Session: Surface and Interface Science of MEMS and NEMS
Presenter: L.M. Fischer, National Institute for Nanotechnology, Canada
Authors: L.M. Fischer, National Institute for Nanotechnology, Canada
N. Wilding, University of Alberta, Canada
M. Gel, National Institute for Nanotechnology, Canada
N. Yang, University of Alberta, Canada
M.T. McDermott, University of Alberta, Canada
S. Evoy, National Institute for Nanotechnology, Canada
Correspondent: Click to Email
Specific immobilization of species is the key to a successful resonant biosensor. Such functionalization of silicon requires a coating of gold/alkane-thiol SAMs to produce stable amine groups that facilitate further binding chemistries. This introduces fabrication complexity and degradation of the resonator properties. PECVD silicon carbonitride (SiCN) has been shown to natively host stable amine groups. Our previous work involving fabrication of nano-structures and analysis of their resonant behavior has determined that SiCN is on par with silicon as a resonant material, and additionally has the advantage of tunable chemical and mechanical properties. We here use ammonia plasma to functionalize the SiCN surface for the immobilization and detection of carcinoembryonic antigen (CEA). The SiCN surface is first populated with N-H groups using a non-depositing ammonia plasma discharge. Similar methods have been used to aminate polymers@footnote 1@ as well as carbon nanofibres@footnote 2@ for biological and gas sensing, respectively. We characterize this modified surface chemistry using FT-IR and XPS, and correlate the resulting surface composition to plasma parameters (time, power, pressure). Fluorescently-tagged streptavidin is used to determine the quantity and density of stable amine groups. Anti-CEA will be immobilized onto the SiCN surface by: (a) direct binding of the antibody to the amine groups, (b) a biotin-streptavidin intermediate, and (c) a succinimide-based molecule. Binding stability and specificity of CEA by these methods will be evaluated through FT-IR and fluorescence microscopy. Fluorination of SiCN via CF@sub 4@ plasma will also be investigated as a means to passivate the surface. @FootnoteText@ @footnote 1@ H.-C. Wen, et al. Surface & Coatings Technol. 200, 3166-3169 (2006)@footnote 2@ K. Nakanishi, et al. Analytical Chemistry 68, 1695-1700 (1996)