Poly(diacetylene) Monolayers Studied with a Fluorescence Scanning Near-Field Optical Microscope

A novel and powerful method to study the optical properties of thin lipid films which a resolution superior to confocal microscopy is presented. With a scanning near-field optical microscope, fluorescence images of a Langmuir-Blodgett film of diethylene glycol diamine pentacosadiynoic amide are obtained with a lateral resolution of 100 nm. Simultaneously a force image is measured that gives the topography. Therefore it is possible to correlate a high-resolution fluorescence micrograph with the topological structure of the polymer film. Polymer domains that do not fluoresce are visible in the force image, while polarization dependence, an optical property not afforded by atomic force microscopy, is clearly demonstrated with a high resolution in the near-field optical image. This combination of fluorescence scanning near field optical microscopy and force microscopy provides additional information o­n the structure of the polymer film that can be valuable in the research of Langmuir-Blodgett films