Preparation of TEM samples for atomistic analyses of QDs. The fishhook (0.5 mg) was added to the Schlenk tube and heated at 120 ℃ under vacuum for 2 hours. After thorough drying the sample and cooled to the room temperature, its atmosphere was exchanged to nitrogen and QDs solution was added to the tube. After stirring it for 24 hours, the reaction mixture was filtered through a PTFE membrane filter (ADVANTEC, pore size: 0.2 μm) and a black filter cake was washed with dried toluene (1 mL ´ 3) under nitrogen flow. The black powder was placed in vacuo (60 Pa) for 1 hour to obtain the sample for TEM (0.45 mg). The black powder of QDs@-CNT forming a large agglomerate was dispersed in toluene (2 mL/mg) under nitrogen flow, and gently ground for 3 minutes in an agate mortar so as to break the agglomerate into individual CNT aggregates for TEM analysis. The dispersion was filtered through Kiriyama 5A filter (pore sizes: 7 μm), and the filtrate (10 μL) was drop casted onto a TEM microgrid (NS-C15) placed on a paper that absorbed excess toluene. The resulting TEM grid was placed in vacuo (60 Pa) at room temperature for 1 hour, which was analyzed by single-molecule atomic-resolution time-resolved electron microscopy (SMART-EM). Using the same conditions, we could not capture QDs on the surface of singlewall CNT (Meijo Arc SO, produced by arc-discharge using Ni and Y catalysts, >90% purity, average diameter 1.4 nm, Lot #1908222), carbon nanohorn (as prepared), nor oxidized carbon nanohorn (treated at 550 ℃ under O2 atmosphere).