title: Fluorescent carbon nanomaterials: "quantum dots" or nanoclusters?
abstract: Despite many efforts, the mechanisms of light absorption and emission of small fluorescent carbon nanoparticles (C-dots) are still unresolved and are a subject of active discussion. In this work we address the question as to whether the fluorescence is a collective property of these nanoparticles or they are composed of assembled individual emitters. Selecting three types of C-dots with "violet", "blue" and "green" emissions and performing a detailed study of fluorescence intensity, lifetime and time-resolved anisotropy as a function of excitation and emission wavelengths together with the effect of viscogen and dynamic fluorescence quencher, we demonstrate that the C-dots represent assemblies of surface-exposed fluorophores. They behave as individual emitters, display electronic anisotropy, do not exchange their excited-state energies via homo-FRET and possibly display sub-nanosecond intra-particle mobility.
authors: Laboratory of Nanobiotechnology, Palladin Institute of Biochemistry, Leontovicha st. 9, Kyiv 01030, Ukraine. dekalyuk_m@mail.ru.
authors: Mariia O
authors: MO
authors: Dekaliuk
authors: Oleg
authors: O
authors: Viagin
authors: Yuriy V
authors: YV
authors: Malyukin
authors: Alexander P
authors: AP
authors: Demchenko
mesh_terms: D002244:Carbon / Q000737:chemistry*; D005454:Fluorescence Polarization; D049329:Nanostructures; D045663:Quantum Dots; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002244:Carbon