Functionalized Carbon Quantum Dots with Dopamine for Tyrosinase Activity Monitoring and Inhibitor Screening: In Vitro and Intracellular Investigation.

Sensitive assay of tyrosinase (TYR) activity is in urgent demand for both fundamental research and practical application, but the exploration of functional materials with good biocompatibility for its activity evaluation at the intracellular level is still challenging until now. In this work, we develop a convenient and real-time assay with high sensitivity for TYR activity/level monitoring and its inhibitor screening based on biocompatible dopamine functionalized carbon quantum dots (Dopa-CQDs). Dopamine with redox property was functionalized on the surface of carbon quantum dots to construct a Dopa-CQDs conjugate with strong bluish green fluorescence. When the dopamine moiety in Dopa-CQDs conjugate was oxidized to a dopaquinone derivative under specific catalysis of TYR, an intraparticle photoinduced electron transfer (PET) process between CQDs and dopaquinone moiety took place, and then the fluorescence of the conjugate could be quenched simultaneously. Quantitative evaluation of TYR activity was established in terms of the relationship between fluorescence quenching efficiency and TYR activity. The assay covered a broad linear range of up to 800 U/L with a low detection limit of 7.0 U/L. Arbutin, a typical inhibitor of TYR, was chosen as an example to assess its function of inhibitor screening, and positive results were observed that fluorescence quenching extent of the probe was reduced in the presence of arbutin. It is also demonstrated that Dopa-CQD conjugate possesses excellent biocompatibility, and can sensitively monitor intracellular tyrosinase level in melanoma cells and intracellular pH changes in living cells, which provides great potential in application of TYR/pH-associated disease monitoring and medical diagnostics.

[1]  Bai Yang,et al.  Self-assembled graphene quantum dots induced by cytochrome c: a novel biosensor for trypsin with remarkable fluorescence enhancement. , 2013, Nanoscale.

[2]  H. Tian,et al.  Target-specific imaging of transmembrane receptors using quinonyl glycosides functionalized quantum dots. , 2014, Analytical chemistry.

[3]  Y. Long,et al.  Monitoring Dopamine Quinone-Induced Dopaminergic Neurotoxicity Using Dopamine Functionalized Quantum Dots. , 2015, ACS applied materials & interfaces.

[4]  R. Halaban,et al.  Novel tyramide‐based tyrosinase assay for the detection of melanoma cells in cytological preparations , 2004, Diagnostic cytopathology.

[5]  X. Qu,et al.  Recent advances in bioapplications of C-dots , 2015 .

[6]  H. Mattoussi,et al.  On the pH-dependent quenching of quantum dot photoluminescence by redox active dopamine. , 2012, Journal of the American Chemical Society.

[7]  Zhiqiang Gao,et al.  Carbon quantum dots and their applications. , 2015, Chemical Society reviews.

[8]  Itamar Willner,et al.  Probing biocatalytic transformations with CdSe-ZnS QDs. , 2006, Journal of the American Chemical Society.

[9]  Xiaoling Yang,et al.  Graphene quantum dots: emergent nanolights for bioimaging, sensors, catalysis and photovoltaic devices. , 2012, Chemical communications.

[10]  R. Boyer.  A spectrophotometric assay of polyphenoloxidase activity. A special project in enzyme characterization. , 1977, Journal of chemical education.

[11]  Shengyong Yan,et al.  A two-photon fluorescent probe for intracellular detection of tyrosinase activity. , 2012, Chemistry, an Asian journal.

[12]  X. Zheng,et al.  Glowing graphene quantum dots and carbon dots: properties, syntheses, and biological applications. , 2015, Small.

[13]  Itamar Willner,et al.  Dopamine-, L-DOPA-, adrenaline-, and noradrenaline-induced growth of Au nanoparticles: assays for the detection of neurotransmitters and of tyrosinase activity. , 2005, Analytical chemistry.

[14]  Wei Ma,et al.  Quinone/hydroquinone-functionalized biointerfaces for biological applications from the macro- to nano-scale. , 2014, Chemical Society reviews.

[15]  Xiaomin Wang,et al.  Kinetic and sensitive analysis of tyrosinase activity using electron transfer complexes: in vitro and intracellular study. , 2015, Small.

[16]  M. Russo,et al.  Regulation of Intracellular pH Mediates Bax Activation in HeLa Cells Treated with Staurosporine or Tumor Necrosis Factor-α* , 2002, The Journal of Biological Chemistry.

[17]  D. Fisher,et al.  Melanocyte biology and skin pigmentation , 2007, Nature.

[18]  Xiaoyuan Chen,et al.  Coenzyme Q functionalized CdTe/ZnS quantum dots for reactive oxygen species (ROS) imaging. , 2011, Chemistry.

[19]  Soonhag Kim,et al.  Carbon nanodot-based self-delivering microRNA sensor to visualize microRNA124a expression during neurogenesis. , 2013, Journal of materials chemistry. B.

[20]  Hongyuan Chen,et al.  CdSe/ZnS quantum dot-Cytochrome c bioconjugates for selective intracellular O2˙⁻ sensing. , 2011, Chemical communications.

[21]  Jun-Mo Yang,et al.  A New Continuous Spectrophotometric Assay Method for DOPA Oxidase Activity of Tyrosinase , 2003, Journal of protein chemistry.

[22]  Joseph Wang,et al.  Spectrophotometric detection of tyrosinase activity based on boronic acid-functionalized gold nanoparticles. , 2012, The Analyst.

[23]  Daoben Zhu,et al.  Synthesis of a new water-soluble oligo(phenylenevinylene) containing a tyrosine moiety for tyrosinase activity detection. , 2008, Organic letters.

[24]  Hui Feng,et al.  Carbon quantum dots-based recyclable real-time fluorescence assay for alkaline phosphatase with adenosine triphosphate as substrate. , 2015, Analytical chemistry.

[25]  Jian Rong Chen,et al.  A real-time fluorescent assay for the detection of alkaline phosphatase activity based on carbon quantum dots. , 2015, Biosensors & bioelectronics.

[26]  S. J. Lee,et al.  Aloesin and arbutin inhibit tyrosinase activity in a synergistic manner via a different action mechanism , 1999, Archives of pharmacal research.

[27]  V. Sharma,et al.  Mushroom tyrosinase: recent prospects. , 2003, Journal of agricultural and food chemistry.

[28]  F. Richard-Forget,et al.  New spectrophotometric assay for polyphenol oxidase activity. , 1993, Analytical biochemistry.

[29]  Hui Feng,et al.  DNA nanosensor based on biocompatible graphene quantum dots and carbon nanotubes. , 2014, Biosensors & bioelectronics.

[30]  F. Hu,et al.  Characteristics of tyrosinase in B16 melanoma. , 1977, The Journal of investigative dermatology.

[31]  Z. Qian,et al.  A universal fluorescence sensing strategy based on biocompatible graphene quantum dots and graphene oxide for the detection of DNA. , 2014, Nanoscale.

[32]  Zhen Gu,et al.  Ubiquinone-quantum dot bioconjugates for in vitro and intracellular complex I sensing , 2013, Scientific Reports.

[33]  H. Feng,et al.  Dual-colored graphene quantum dots-labeled nanoprobes/graphene oxide: functional carbon materials for respective and simultaneous detection of DNA and thrombin , 2014, Nanotechnology.

[34]  P. Fishman,et al.  Tyrosinase as an autoantigen in patients with vitiligo , 1996, Clinical and experimental immunology.

[35]  E. Wang,et al.  Ratiometric fluorescence detection of tyrosinase activity and dopamine using thiolate-protected gold nanoclusters. , 2015, Analytical chemistry.

[36]  Igor L. Medintz,et al.  Quantum-dot/dopamine bioconjugates function as redox coupled assemblies for in vitro and intracellular pH sensing. , 2010, Nature materials.

[37]  Hui Feng,et al.  Simultaneous detection of multiple DNA targets by integrating dual-color graphene quantum dot nanoprobes and carbon nanotubes. , 2014, Chemistry.

[38]  T. Shin,et al.  Effects of α- and β-Arbutin on Activity of Tyrosinases from Mushroom and Mouse Melanoma , 1995 .

[39]  D. Tobin,et al.  Melanin pigmentation in mammalian skin and its hormonal regulation. , 2004, Physiological reviews.

[40]  Itamar Willner,et al.  Electrochemical, photoelectrochemical, and piezoelectric analysis of tyrosinase activity by functionalized nanoparticles. , 2008, Analytical chemistry.

[41]  Shengyong Yan,et al.  A turn-on fluorescent probe for detection of tyrosinase activity. , 2013, The Analyst.

[42]  M. Friedman.  Food browning and its prevention: an overview , 1996 .

[43]  Itamar Willner,et al.  Probing biocatalytic transformations with luminescent DNA/silver nanoclusters. , 2013, Nano letters.

[44]  S. N. Baker,et al.  Luminescent Carbon Nanodots: Emergent Nanolights , 2011 .

[45]  T. Kuriki,et al.  Syntheses of Arbutin-α-glycosides and a Comparison of Their Inhibitory Effects with Those of α-Arbutin and Arbutin on Human Tyrosinase , 2003 .

[46]  O. Wolfbeis,et al.  A near-infrared fluorescent probe for monitoring tyrosinase activity. , 2010, Chemical communications.

[47]  Jian Dong,et al.  Growth-sensitive gold nanoshells precursor nanocomposites for the detection of L-DOPA and tyrosinase activity. , 2011, Biosensors & bioelectronics.

[48]  Z. Qian,et al.  A reversible fluorescence nanoswitch based on carbon quantum dots nanoassembly for detection of pyrophosphate ion , 2015 .

[49]  Zhen Cheng,et al.  Amino-functionalized green fluorescent carbon dots as surface energy transfer biosensors for hyaluronidase. , 2015, Nanoscale.