Investigations at nanoscale by using fluorescence in apertureless scanning near field microscopy

Fluorescence apertureless near-field optical microscopy (FASNOM) gained interest from researchers in the last years because of its promising capabilities: sub-wavelength resolution and ability to exploit the chemical sensitivity of fluorescent tags. FASNOM exploits the fact that metallic structures in close proximity of a fluorophore or a photoluminescent sample have complex effects on fluorescence, inducing changes in both fluorescence lifetime and emission intensity. The detection concept of FASNOM is based on the periodic perturbation of the interaction between a fluorescent sample and the excitation beam by using a sharp probe. The aim of the present work is to present the tip enhanced near field fluorescence and topography characterization of collagen by using an atomic force microscope upgraded with an apertureless microscope.