title: Monitoring Dynamic Cellular Redox Homeostasis Using Fluorescence-Switchable Graphene Quantum Dots.
abstract: Monitoring cellular redox homeostasis is critical to the understanding of many physiological functions ranging from immune reactions to metabolism, as well as to the understanding of pathological development ranging from tumorigenesis to aging. Nevertheless, there is currently a lack of appropriate probes for this ambition, which should be reversibly, sensitively, and promptly responsive to a wide range of physiological oxidants and reductants. In this work, a redox-sensitive fluorescence-switchable probe is designed based on graphene quantum dots (GQDs) functionalized with a chelated redox Fe2+/Fe3+couple. The underlying mechanism is investigated and discussed. The high sensitivity and fast response are attributable to the fact that the GQD's photoluminescence is highly sensitive to photon-induced electron transfer because of its ultrasmall size and associated prominent quantum confinement effect. Also taking advantages of GQDs' excellent photostability, biocompatibility, and readiness for cell uptake, our reversibly tunable fluorescence probe is employed to monitor in real time the triggered dynamic change of the intracellular redox state. This addition to the limited arsenal of available redox probes shall be useful to the still poorly understood redox biology, as well as for monitoring environment or chemical processes involving redox reactions.
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Nan
authors.initials: N
authors.lastname: Li
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Aung
authors.initials: A
authors.lastname: Than
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Chencheng
authors.initials: C
authors.lastname: Sun
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Jingqi
authors.initials: J
authors.lastname: Tian
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Kanyi
authors.identifier: 0000-0002-8064-6009
authors.initials: K
authors.lastname: Pu
authors.affiliation: Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech) , 30 South Puzhu Road, Nanjing 211816, China.
authors.forename: Xiaochen
authors.initials: X
authors.lastname: Dong
authors.affiliation: Division of Bioengineering, School of Chemical & Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Peng
authors.identifier: 0000-0003-3730-1846
authors.initials: P
authors.lastname: Chen
keywords: fluorescent probes; graphene quantum dots; live cell imaging; redox homeostasis