 The paper investigates the size-dependent endocytosis of gold nanoparticles, AUNPs, in living cells using plasmonic scattering images without any labelling. AUNPs have large optical scatterings at 550 to 600 nanometers wavelength due to localized surface plasmon resonances, which can be used to distinguish them from cellular organelles. The tracking of AUNPs coated with aptomers for surface musing glycoprotein shows that AUNPs attach to extracellular matrix and move towards the center of the cell. Most 75 NMAUNPs move to the top of cells, while many 45 NMAUNPs entered cells through endocytosis and accumulated in endocytic vesicles. The amounts of cellular uptake decreased with the increase of particle size. The paper concludes that the plasmonic scattering images confirm the size-dependent endocytosis of AUNPs, and the 45 NMAUNP is better for drug delivery due to its higher uptake rate. Large AUNPs are immobilized on the cell membrane and can be used to reconstruct the cell morphology. This article was authored by Li Kewei, Wang Shenghan, Chu Arthur, and others. We are article.tv, links in the description below.