title: Target-Activated Modulation of Dual-Color and Two-Photon Fluorescence of Graphene Quantum Dots for in Vivo Imaging of Hydrogen Peroxide.
abstract: The development of nanoprobes suitable for two-photon microscopy techniques is highly desirable for mapping biological species in living systems. However, at the current stage, the nanoprobes are restricted to single-color fluorescence changes, making it unsuitable for quantitative detection. To circumvent this problem, we report here a rational design of a dual-emission and two-photon (TP) graphene quantum dot (GQD(420)) probe for imaging of hydrogen peroxide (H2O2). For specific recognition of H2O2 and lighting the fluorescence of TPGQD(420), a boronate ester-functionalized merocyanine (BMC) fluorophore was used as both target-activated trigger and the dual-emission fluorescence modulator. Upon two-photon excitation at 740 nm, TPGQD(420)-BMC displays a green-to-blue resolved emission band in response to H2O2 with an emission shift of 110 nm, and the H2O2 can be determined from 0.2 to 40 μM with a detection limit of 0.05 μM. Moreover, the fluorescence response of the TPGQD(420)-BMC toward H2O2 is rapid and extremely specific. The feasibility of the proposed method is demonstrated by two-photon ratiometrically mapping the production of endogenous H2O2 in living cells as well as in deep tissues of murine mode at 0-600 μm. To the best of our knowledge, this is the first paradigm to rationally design a dual-emission and two-photon nanoprobe via fluorescence modulation of GQDs with switchable molecules, which will extend new possibility to design powerful molecular tools for in vivo bioimaging applications.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Yinhui
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Chemistry and Biological Engineering, Changsha University of Science and Technology , Changsha, 410004, People's Republic of China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Changhui
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Chemistry and Biological Engineering, Changsha University of Science and Technology , Changsha, 410004, People's Republic of China.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Qing
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.
authors.forename: Jishan
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and Collaborative Innovation Center for Chemistry and Molecular Medicine, Hunan University , Changsha, 410082, People's Republic of China.|School of Chemistry and Biological Engineering, Changsha University of Science and Technology , Changsha, 410004, People's Republic of China.
authors.forename: Ronghua
authors.initials: R
authors.lastname: Yang
mesh_terms: D003116:Color; D005453:Fluorescence; D006108:Graphite / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D007089:Image Enhancement; D008856:Microscopy, Fluorescence; D017785:Photons; D045663:Quantum Dots
chemical_list: D006108:Graphite; D006861:Hydrogen Peroxide