Fluorescent carbon nanoparticles are grafted with azobenzene dendrons, giving unique dendronized carbon nanoparticles that exhibit an increased quantum yield by as much as ∼74% at a low concentration. Such an improvement is attributed to the strong light harvesting capability of grafted azobenzene dendrons that act as "light antenna" to collect photons and the excitons generated then traverse to adjacent central carbon nanoparticles. © 2014 The Partner Organisations.