Abstract: The investigations on inter- or intra-molecular interactions in polymer systems at the single-molecule level are of pivotal importance in revealing the relationship between structure and function and eventually getting good controls on the corresponding function. Atomic force microscopy(AFM)-based single-molecule force spectroscopy(SMFS) has been used widely in the field of single-molecule study due to its friendly user interface(i.e., easy to use and can work in both aqueous solution and organic solvents) and world-wide commercialization. In this article, we introduced recent advancements in AFM-based single-molecule force spectroscopy study of polymer(including biopolymer and synthetic polymer) interactions. For biopolymer system, we first introduced typical force fingerprints of nucleic acid, protein and polysaccharides, and then discussed the force-fingerprint-based investigation of molecular interactions. For synthetic polymer system, the relationship between primary structure and single chain elasticity was discussed first, and then the effects of both single chain aggregates and the bulk aggregates on the elasticity of polymer chains were discussed.

Key words: Single-molecule force spectroscopy, Biopolymer, Synthetic polymer, Virus, Polymer single crystal