title: A new class of fluorescent-dots: long luminescent lifetime bio-dots self-assembled from DNA at low temperatures.
abstract: Quantum-dots (QDs) have fuelled up intensive research efforts over the past two decades. Nevertheless, currently developed two classes of fluorescent QDs, colloidal semiconductor QDs and carbonaceous QDs suffer from either toxicity or short luminescence lifetime. Here, we report a new class of fluorescent bio-dots that are derived from DNA via self-assembly at low temperatures down to 80°C, which has an optical bandgap of 3.4 eV, and in particular possesses strong photoluminescence with a much longer luminescence lifetime (τ₁ = 10.44 ns) than the carbonaceous QDs (τ₁ < 0.5 ns). It is discovered that it is the interactions of base pair cytosines with each other to form sp² carbon-like centers as luminescence centers or chromophores for the photoluminescence. The use of bio-dots in cell imaging with strong photoluminescence signal and good biocompatibility demonstrates great potentials of broad biological and optoelectronic applications.
authors.affiliation: 1] Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715, P. R. China [2] Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Chongqing 400715, P. R. China.
authors.forename: Chun Xian
authors.initials: CX
authors.lastname: Guo
authors.forename: Jiale
authors.initials: J
authors.lastname: Xie
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Xinting
authors.initials: X
authors.lastname: Zheng
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Yang
authors.forename: Chang Ming
authors.initials: CM
authors.lastname: Li
mesh_terms: D004247:DNA / Q000737:chemistry*; D008163:Luminescent Measurements; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D008968:Molecular Conformation; D057054:Molecular Imaging; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D013696:Temperature
chemical_list: D004247:DNA