title: A new hydrothermal refluxing route to strong fluorescent carbon dots and its application as fluorescent imaging agent.
abstract: Due to their unique optical and biochemical properties, the water-soluble fluorescent carbon dots (CDs) have attracted a lot of attention recently. Here, strong fluorescent carbon dots with excellent quality have been synthesized by the hydrothermal refluxing method using lactose as carbon source and tris(hydroxymethyl) aminomethane (i.e. Tris) as surface passivation reagent. This facile approach was simple, efficient, economical, green without pollution, and allows large-scale production of CDs without any post-treatment. TEM measurements showed that the resulting particles exhibited an average diameter of 1.5 nm. The obtained CDs possess small particle sizes, good stability in a wide range of pH values (pH 3.5-9.5), high tolerance of salt concentration, strong resistibility to photobleaching, and a fluorescent quantum yield up to 12.5%. The CDs were applied to optical bioimaging of HeLa cells, showing low cytotoxicity and excellent biocompatibility.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, Department of Chemistry, Nankai University, Tianjin 300071, China.
authors.forename: Ye-Yun
authors.initials: YY
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.forename: Yan-Qin
authors.initials: YQ
authors.lastname: Wang
authors.forename: Xi-Wen
authors.initials: XW
authors.lastname: He
authors.forename: Wen-You
authors.initials: WY
authors.lastname: Li
authors.forename: Xi-Zeng
authors.initials: XZ
authors.lastname: Feng
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002470:Cell Survival / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007785:Lactose / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000138:chemical synthesis* / Q000494:pharmacology / Q000648:ultrastructure; D010316:Particle Size; D045663:Quantum Dots / Q000737:chemistry* / Q000633:toxicity / Q000648:ultrastructure; D014325:Tromethamine / Q000737:chemistry
chemical_list: D015335:Molecular Probes; D014325:Tromethamine; D002244:Carbon; D007785:Lactose
keywords: Carbon dots; Fluorescence; Hydrothermal refluxing; Imaging; Lactose; Tris