Zero-Mode Waveguides for Single-Molecule Analysis at High Concentrations

Author(s): Levene, M.J., J. Korlach, S.W. Turner, M. Foquet, H.G. Craighead, W.W. Webb

Journal: Science (2003) 299: 682-686.

Abstract:
Optical approaches for observing the dynamics of single molecules have required pico- to nanomolar concentrations of fluorophore in order to isolate individual molecules. However, many biologically relevant processes occur at micromolar ligand concentrations, necessitating a reduction in the conventional observation volume by three orders of magnitude. We show that arrays of zero-mode waveguides consisting of subwavelength holes in a metal film provide a simple and highly parallel means for studying single-molecule dynamics at micromolar concentrations with microsecond temporal resolution. We present observations of DNA polymerase activity as an example of the effectiveness of zero-mode waveguides for performing single-molecule experiments at high concentrations.