title: Conjugation of quantum dots with graphene for fluorescence imaging of live cells.
abstract: It is difficult to achieve fluorescent graphene-quantum dots (QDs) conjugation because graphene quenches the fluorescence of the QDs. In the present study, the conjugation of graphene (reduced graphene oxide, RGO) with QDs via a bridge of bovine serum albumin (BSA) provides a novel highly fluorescent nano probe for the first time. BSA capped QDs are firmly grafted onto polyethylenimine (PEI)/poly(sodium 4-styrenesulfonate) (PSS) coated RGO (graphene-QDs) via electrostatic layer by layer assembly. The strong luminescence of the graphene-QDs provides a potential for non-invasive optical in vitro imaging. The graphene-QDs are used for in vitro imaging of live human carcinoma (Hela) cells. Graphene-QDs could be readily up-taken by Hela cells in the absence of specific targeting molecules, e.g., antibodies or folic acid, and no in vitro cytotoxicity is observed at 360 μg mL(-1) of the graphene-QDs. The results for the imaging of live cells indicated that the cell-penetrating graphene-QDs could be a promising nano probe for intracellular imaging and therapeutic applications.
authors: Research Center for Analytical Sciences, Northeastern University, Box 332, Shenyang, 110819, China.
authors: Mei-Ling
authors: ML
authors: Chen
authors: Jia-Wei
authors: JW
authors: Liu
authors: Bo
authors: B
authors: Hu
authors: Ming-Li
authors: ML
authors: Chen
authors: Jian-Hua
authors: JH
authors: Wang
mesh_terms: D000818:Animals; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry* / Q000633:toxicity; D006367:HeLa Cells; D006801:Humans; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D011094:Polyethyleneimine / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D045663:Quantum Dots; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D011137:Polystyrenes; D012710:Serum Albumin, Bovine; C003321:polystyrene sulfonic acid; D006108:Graphite; D011094:Polyethyleneimine