| AVS 55th International Symposium & Exhibition | |
| MEMS and NEMS | Tuesday Sessions |
| Session MN-TuM |
| Session: | Materials Processing and Characterization for MEMS/NEMS |
| Presenter: | C. Guthy, University of Alberta and National Institute for Nanotechnology, Canada |
| Authors: | C. Guthy, University of Alberta and National Institute for Nanotechnology, Canada L.M. Fischer, University of Alberta and National Institute for Nanotechnology, Canada V.A. Wright, University of Alberta and National Institute for Nanotechnology, Canada A. Singh, University of Alberta and National Institute for Nanotechnology, Canada J.M. Buriak, University of Alberta and National Institute for Nanotechnology, Canada S. Evoy, University of Alberta and National Institute for Nanotechnology, Canada |
| Correspondent: | Click to Email |
Rapid, sensitive and inexpensive analysis of biological molecules is vital to disease detection, monitoring, drug discovery. For instance, the detection and identification of biomarker proteins of diseases such as metabolic disorders, multiple sclerosis and cancer have gained considerable attention over the recent years. Detection of such proteins with high specificity at very low concentrations would greatly facilitate diagnostic and help predict disease progression. Current analytical technologies such as DNA microarray, mass spectrometry and nuclear magnetic resonance spectroscopy are expensive and technically challenging for clinical applications. Mechanical resonators have been demonstrated as highly sensitive transducers for the detection of molecular systems. The sensitivity of resonators scales favorably as their dimensions are reduced, offering a compelling path for the development of sensors with exceptional mass sensitivities. To enable the specificity of detection, various analyte-specific functional layers need to be immobilized onto the surface of resonators. Such resonators could be then used as sensing arrays for the analysis of complex protein mixtures. As a proof of concept, we recently demonstrated the specific detection of streptavidin using doubly-clamped nanomechanical resonators (bridges) functionalized with biotin. Bridges with widths down to 300 nm were realized from silicon carbonitride (SiCN) thin films using a novel fabrication method. Based on the shift of resonant frequency, a mass of 3.6 fg/µm2 was attributed to the added streptavidin, corresponding to one molecule per 27 nm2. We have since further scaled down the dimensions of our devices and have demonstrated the surface machining of resonators of world record lateral dimensions of 40 nm with a yield approaching 100%. These 15 µm long resonators show resonance frequencies of ~ 11 MHz with quality factors of ~ 5000 in the mTorr pressure range. We will present a thorough investigation of the resonant behavior of these novel sub-100nm NEMS devices of various dimensions. We are also developing the attachment of antibodies onto these resonators. The specific detection of human interferon gamma (IFN-γ) protein was chosen as target system. Our ultimate goal is to use similar immobilization procedures for the detection of disease biomarkers, including but not limited to multiple sclerosis biomarkers.