Single molecule force spectroscopy (SMFS) was utilized to study single-molecule interactions between synthesized polymers and MoS2 surfaces that provide the guidance to determine candidate polymers for efficient aqueous exfoliation of bulk MoS2 into single-layer nanosheets. The technique allowed the direct quantification of the adhesion force of single polymer molecules with both basal and edge surfaces of MoS2. Compared with two studied neutral polymers, highly water-soluble cationic poly(vinylbenzyl trimethyl ammonium chloride) (PVBTA) was shown to be more promising for MoS2 exfoliation as a result of strong single-molecule interactions with both basal and edge surfaces of MoS2. In 1 mM NaCl solution of pH around 5.5, the measured single-molecule adhesion forces on basal and edge surfaces were around 59 and 51 pN, respectively. Such strong adhesion force led to high performance of PVBTA in exfoliating MoS2 bulk material into single-layer sheets. Compared with reported approaches in the literatures, an o...