Zero-mode waveguides for single-molecule analysis.

We review the optical properties, fabrication, and applications of zero-mode waveguides (ZMWs) for single-molecule studies. These simple nano-structures allow individual molecules to be isolated for optical analysis at high concentrations. Fluorescent species are observed in a sufficiently small volume that the average number of fluorescent molecules is less than one, even at concentrations high enough for biochemical reactions to proceed at normal rates.