Assembly of nanoparticles at the contact line of a drying droplet under the influence of a dipped tip

► Assembly of nanoparticles can be controlled by manipulating the contact line pinning. ► Dipping a tip into drying droplet alters the behavior of nanoparticles. ► Tip surface chemistry influences the assembly of nanoparticles in the droplet. ► Different concentric ring formation mechanisms for hydrophilic and hydrophobic tips.