Near field optical microscopy for subwavelength investigation of biological structures

Applications of scanning near field optical microscopy to the imaging and the structuring of biomolecules is presented. The paper introduces the technique and presents images of a test grating, showing the potential of the technique for subwavelength imaging in air as well as in water. A sub-micrometer size fiber tip characterized by its high transmission is presented as an interesting probe for near field fluorescence microscopy. The potential of the technique is exploited to detect bioactive molecules that have been marked with a fluorescent probe and photoimmobilized onto a glass substrate using near field UV-activation of a photolinker.