Unmodified single nanoparticles undergo a motion-pattern transition on the plasma membrane before cellular uptake

•Unmodified gold nanorods do “touch-and-bounce” motion in initial-adsorption stage.•Unmodified gold nanorods do “hop-diffusion” motion in membrane-diffusion stage.•Driving force changes from electrostatic interaction to ligand-receptor interaction.•Protein-corona change causes the motion-pattern transition and unmodified nanoparticles cytofriendly.