Invited Speaker - Stephane Evoy

Nanomechanical Resonator Arrays for the Specific Detection of Proteins

Detection of biological and chemical agents is critical to many life sciences areas including disease diagnosis, drug molecule screening, and rapid analysis of various molecular systems. Micro- and nanoresonators have also been shown to be promising platforms for such tagless analysis. The mass sensitivity of mechanical resonators scales favorably as their mass is reduced, offering a compelling path for the development of large arrays of devices offering exceptional sensitivities. An overview of activities concerning the development of such nanoresonator arrays will be presented. In a first approach, we have developed a novel surface nanomaching procedure allowing the fabrication of resonators as narrow as 15 nm with a yield approaching 100%. This approach also does not require a critical point drying step which is known to leave residues onto the device surfaces. Alternatively, the last few years have also seen the development of alternate "bottom-up" techniques for the fabrication of nanodevices. For example, silicon nanowires have been used to detect biological and chemical species. These sensors operate by monitoring changes of electrical conductivity associated to the binding. In this work, the specific detection of proteins using nanowires was rather achieved through the monitoring of their mechanical resonance. The read-out of both surface-machined and surface-grown nanowires was performed using an all-optical method of actuation and detection, preventing the need of electrical contacts to the individual devices. The specific detection of streptavidin using biotin as molecular probe was demonstrated as proof of concept in both types of devices.

Dr. Stephane Evoy (NINT/UofA) received a B. Ing and M.Sc.A in Engineering Physics from the Ecole Polytechnique de Montréal, in 1992 and 1994, respectively. He also received Ph.D. in Applied Physics from Cornell University in 1998. He is currently an Associate Professor in the Department of Electrical and Computer Engineering at the University of Alberta, as well as a Principal Investigator - Devices and Sensors at the National Institute for Nanotechnology in Edmonton. Dr. Evoy has co-authoredover 60 papers and presentations in the area of nanoelectromechanical systems (NEMS),nanosensors, nanofabrication, and scanning probe microscopy. He co-edited the 2004 textbook:"Introduction to Nanoscale Science and Engineering." His own research currently focuses on cantilever- and SPR-based detection of proteins and pathogens, as well as the development of bioassay platforms based on large arrays of nanomechanical resonators.