Fluorescence Correlation Spectroscopy as a Versatile Method to Define Aptamer-Protein Interactions with Single-Molecule Sensitivity.

Aptamers are folded oligonucleotides that selectively recognize and bind a target and are consequently regarded as an emerging alternative to antibodies for sensing and therapeutic applications. The rational development of functional aptamers is strictly related to the accurate definition of molecular binding properties. Nevertheless, most of the methodologies employed to define binding affinities use bulk measurements.