Single biomolecule binding studies in spatially restricted fluid systems

Harold G. Craighead School of Applied and Engineering Physics, The Nanobiotechnology Center, Cornell University, 205 Clark Hall, Ithaca, NY 14853, U.S.A. e-mail: hgc1@cornell.edu URL: http://www.hgc.cornell.edu and http://www.nbtc.cornell.edu

We have used simple nanofluidic devices to isolate individual active biomolecules in solution in order to optically observe there activity and identity. We have employed metallic apertures a few tens of nanometers in diameter to confine a region of optical excitation to a volume on the order of 10^-20 liters, which allows for the observation of single molecule binding activity at meaningful rates and concentrations. Small fluid channels have also been used to isolate individual optically detected molecules. Temporal observation of the either driven or diffusive motion of molecules through the restricted observation volumes provides information about the identity of the molecule and can also be used to detect specific chemical binding events. Single specific molecular binding events can be observed by optically observing the spectral characteristics of labeled molecules. In this talk we will describe several approaches and applications of the single molecule binding studies.