It is crucial to understand the behaviour and interfacial interactions as well as properties of ionic liquids (ILs) at electrode surfaces on the molecular level for developing IL-based electrochemical energy storage devices including supercapacitors and batteries. In this work, a colloid probe atomic force microscopy (CP-AFM) -based experimental approach is presented to determine the molecular interaction forces between ILs and differently charged SiO₂ microspheres. The effects of structural variations in ILs and the nature surface charges of SiO₂ on the molecular interaction force are systematically studied. The surface charges of SiO₂ were achieved by grafting quaternary ammonium and –COOH, –NH₂ groups. The determined molecular interaction force is found to be strongly dependent on the surface charge, in which, the force enhances at a more negatively charged surface. Furthermore, the ILs with longer alkyl chains on cations exhibit stronger molecular interaction forces with the charged SiO₂. These reported experimental results on the molecular level provide new insights for model development and molecular simulations of ILs interacting with charged surfaces and guide the design of ILs-based supercapacitor and battery systems.