Scanning near-field optical microscopy-based study of local dynamics of receptor-ligand interactions at the single molecule level

A scanning near-field optical microscope (SNOM)—based modification of the method to study the dynamics of single molecule receptor—ligand interactions exploiting the fluorescence imaging by total internal reflection fluorescence microscopy is introduced. The main advantage of this approach consists in the possibility to study the single molecule interaction dynamics with a subwavelength spatial resolution and a submillisecond time resolution. Additionally, due to the much smaller irradiation area and some other technical features, such a modification enables to enlarge the scope of the receptor—ligand pairs to be investigated and to improve the temporal resolution. We briefly discuss corresponding experimental set up with a special accent on the SNOM operation in liquid and present some preliminary results of related investigations.