10000 times volume reduction for fluorescence correlation spectroscopy using nano-antennas

We present an experimental and theoretical study of a new scheme for Near-Field Fluorescence Correlation Spectroscopy that, using the field enhancement by optical nanoantennas, allows the reduction of the observation volume 4 orders of magnitude below the diffraction limit. This reduction can be used in two different ways: to increase the sample concentration and to improve the spatial resolution of the dynamics under study. Our experimental results using individual gold nanoparticles and a 150 mu M Rose Bengal solution in glycerol confirm the volume reduction. (C) 2008 Optical Society of America