Field enhancement and apertureless near-field optical spectroscopy of single molecules

We report on fluorescence enhancement in near field optical spectroscopy by apertureless microscopy. Our apertureless microscope is designed around a confocal fluorescence microscope associated with an AFM head. First, we show that the confocal microscope alone allows single molecule imaging and single molecule fluorescence analysis. When associated with the AFM head, we demonstrate, for the first time to our knowledge, that single molecule fluorescence is enhanced under the silicon tip. We tentatively attribute this effect to field enhancement under the tip.