@article{2320a288aa114c6192db010782783bda,
title = "Activity-Based Sensing of Ascorbate by Using Copper-Mediated Oxidative Bond Cleavage",
abstract = "Ascorbate is an important biological reductant and enzyme cofactor. Although direct detection through ascorbate-mediated reduction is possible, this approach suffers from poor selectivity due to the wide range of cellular reducing agents. To overcome this limitation, we leverage reduction potential of ascorbate to mediate a copper-mediated oxidative bond cleavage of ether-caged fluorophores. The copper(II) complexes supported by a {bis(2-pyridylmethyl)}benzylamine or a {bis(2-pyridylmethyl)}(2-methoxybenzyl)amine ligand were identified as an ascorbate responsive unit and their reaction with ascorbate yields a copper-based oxidant that enables rapid benzylic oxidation and the release of an ether-caged dye (coumarin or fluorescein). The copper-mediated bond cleavage is specific to ascorbate and the trigger can be readily derivatized for tuning photophysical properties of the probes. The probes were successfully applied for the fluorometric detection of ascorbate in commercial food samples, human plasma, and serum, and within live cells by using confocal microscopy and flow cytometry.",
keywords = "ascorbate, copper, fluorescent probes, oxidation, sensors",
author = "Yu, {Zuo Hang} and Reinhardt, {Christopher J.} and Wong, {Thomas Hin Fung} and Tong, {Ka Yan} and Jefferson Chan and Au-Yeung, {Ho Yu}",
note = "Funding Information: This work was supported by the Croucher Foundation and the Research Grants Council of the Hong Kong Special Administrative Region, China (HKU 106150183). Z.H.Y. is a recipient of the Postgraduate Scholarship from The University of Hong Kong. C.J.R. thanks the Chemistry–Biology Interface Training Grant (T32GM070421). We thank Dr. C. N. Lok, Dr. A. Y. Z. Lai, and Dr. Y. Yang for their assistance in initial experiments. We acknowledge UGC funding administered by The University of Hong Kong for supporting the Electrospray Ionization Quadrupole Time‐of‐Flight Mass Spectrometry Facilities under the Support for Interdisciplinary Research in Chemical Science. We also acknowledge the Core Facilities at the Carl R. Woese Institute for Genomic Biology for access to the Zeiss LSM 700 Confocal Microscope and corresponding software. We acknowledge support from the HKU Li Ka Shing Faculty of Medicine Imaging and Flow Cytometry Core for access to the BD LSR Fortessa Analyzer. Publisher Copyright: {\textcopyright} 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim",
year = "2020",
month = jul,
day = "17",
doi = "10.1002/chem.202000780",
language = "English (US)",
volume = "26",
pages = "8794--8800",
journal = "Chemistry - A European Journal",
issn = "0947-6539",
publisher = "Wiley-VCH",
number = "40",
}