title: Graphene quantum dots with nitrogen-doped content dependence for highly efficient dual-modality photodynamic antimicrobial therapy and bioimaging.
abstract: Reactive oxygen species is the main contributor to photodynamic therapy. The results of this study show that a nitrogen-doped graphene quantum dot, serving as a photosensitizer, was capable of generating a higher amount of reactive oxygen species than a nitrogen-free graphene quantum dot in photodynamic therapy when photoexcited for only 3 min of 670 nm laser exposure (0.1 W cm-2), indicating highly improved antimicrobial effects. In addition, we found that higher nitrogen-bonding compositions of graphene quantum dots more efficiently performed photodynamic therapy actions than did the lower compositions that underwent identical treatments. Furthermore, the intrinsically emitted luminescence from nitrogen-doped graphene quantum dots and high photostability simultaneously enabled it to act as a promising contrast probe for tracking and localizing bacteria in biomedical imaging. Thus, the dual modality of nitrogen-doped graphene quantum dots presents possibilities for future clinical applications, and in particular multidrug resistant bacteria.
authors.affiliation: Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan, ROC. Electronic address: wenshuokuo@mail.ncku.edu.tw.
authors.forename: Wen-Shuo
authors.initials: WS
authors.lastname: Kuo
authors.affiliation: Department of Food Science, National Penghu University of Science and Technology, Penghu 880, Taiwan, ROC.
authors.forename: Hua-Han
authors.initials: HH
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Shih-Yao
authors.initials: SY
authors.lastname: Chen
authors.affiliation: Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Chia-Yuan
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Pei-Chi
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Yung-I
authors.initials: YI
authors.lastname: Hou
authors.affiliation: Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Department of Microbiology & Immunology, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Shao
authors.affiliation: Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Department of Nursing, National Tainan Junior College of Nursing, Tainan 700, Taiwan, ROC.
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Kao
authors.affiliation: Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC; Department of Microbiology & Immunology, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Chih-Li
authors.initials: CL
authors.lastname: Lilian Hsu
authors.affiliation: Department of Physics, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Yi-Chun
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan, ROC.
authors.forename: Shean-Jen
authors.initials: SJ
authors.lastname: Chen
authors.affiliation: Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC; Institute of Oral Medicine, National Cheng Kung University, Tainan 701, Taiwan, ROC. Electronic address: z10208056@email.ncku.edu.tw.
authors.forename: Shang-Rung
authors.initials: SR
authors.lastname: Wu
authors.affiliation: Allergy & Clinical Immunology Research Center, National Cheng Kung University, Tainan 701, Taiwan, ROC; Institute of Basic Medical Sciences, National Cheng Kung University, Tainan 701, Taiwan, ROC; Department of Microbiology & Immunology, National Cheng Kung University, Tainan 701, Taiwan, ROC. Electronic address: a122@mail.ncku.edu.tw.
authors.forename: Jiu-Yao
authors.initials: JY
authors.lastname: Wang
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage; D058948:Cell Tracking / Q000379:methods; D004926:Escherichia coli / Q000166:cytology* / Q000187:drug effects*; D006108:Graphite / Q000627:therapeutic use; D008163:Luminescent Measurements / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D045663:Quantum Dots / Q000627:therapeutic use*; D000068936:Theranostic Nanomedicine / Q000379:methods*
chemical_list: D000890:Anti-Infective Agents; D017319:Photosensitizing Agents; D006108:Graphite; D009584:Nitrogen
keywords: Antimicrobial; Contrast probe; Nitrogen-doped graphene quantum dot; Photodynamic therapy; Photostability; Reactive oxygen species