The objective of this work was to characterize and, thereby, achieve a fundamental scientific understanding at the molecular level of the relationship of the intermolecular forces measured at the nanoscale between an individual nanoparticle and a polymer. In this study, we developed a method to directly characterize and measure the relative strength of the interfacial attractive forces between graphene oxide (GO) nanoparticles and the polymer matrix on the nanoscale using atomic force microscopy techniques to evaluate individual particles. The method was successfully applied to study the interfacial attractive forces in GO-polymer nanocomposites. Two polymers [poly(methyl methacrylate) and poly(vinyl alcohol)] were studied. The results support that this method is capable of characterizing the interfacial attractive forces directly at the nanoscale. The method can be applied to other nanoparticle-macromolecular systems, allowing the determination of the interaction strength between nanopartides and the macromolecular material. This information paves the way to characterize the relationship between interfacial forces at the nanometer level to a nanocomposite's performance properties. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3740-3744, 2011