Self-assembled or grafted onto organic monolayers bound to a solid surface, like polymer brushes, have versatile uses. They serve as detection layers for specific biomolecules in biosensors or as protective coatings in tribological systems or lab-on-chip devices. Understanding how the unbound section of the polymer brush is structured and how it interacts with liquid surroundings is crucial for these applications, especially at the nanometric scale. Our study aims to characterize this liquid/polymer brush interface using force spectroscopy, or 1D-AFM, as well as considering the 3D-AFM mode developed by T. Fukuma and R. Garcia [1]. In this mode, a 2D cross-sectional image (xz) representing the liquid organization at the interface is constructed from the recording of frequency variations Δf during scanning. We particularly focus on thiol-based interfaces deposited on a pure gold surface in a liquid medium, aiming for applications in biosensors and tribology [2]. Three samples were studied: ultra-flat pure gold, pure Poly(acrylic acid) PAA, and pure Poly(ethylene oxide) PEO. The polymers were observed in liquids with different pH levels: after treatment with HCl to create an acidic solution (pH = 4), in pure water (pH = 5.5), and in PBS (pH = 7.4). We also tested them in salt-concentrated solutions achieved by including NaCl. The force curves obtained with 1D-AFM measurements show the effect of different liquid environments on the behavior of the polymer chain, manifested as changes in the chain length. 3D-AFM measurements complement the obtained results, and our initial experiments suggest that this method is well-suited for visualizing the organization of the liquid molecules and ions on the polymer brush layer, and its dependence on variations in pH and ionic concentration.