AUTHOR=Sugita Ko , Tsuchido Yuji , Kasahara Chisato , Casulli Maria Antonietta , Fujiwara Shoji , Hashimoto Takeshi , Hayashita Takashi 

TITLE=Selective Sugar Recognition by Anthracene-Type Boronic Acid Fluorophore/Cyclodextrin Supramolecular Complex Under Physiological pH Condition

JOURNAL=Frontiers in Chemistry

VOLUME=7

YEAR=2019

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2019.00806

DOI=10.3389/fchem.2019.00806

ISSN=2296-2646

ABSTRACT=<p>We synthesized novel PET (photoinduced electron transfer)-type fluorescence glucose probe <bold>1</bold> [(4-(anthracen-2-yl-carbamoyl)-3-fluorophenyl)boronic acid], which has a phenylboronic acid (PBA) moiety as the recognition site and anthracene as the fluorescent part. Although the PBA derivatives dissociate and bind with sugar in the basic condition, our new fluorescent probe can recognize sugars in the physiological pH by introducing an electron-withdrawing fluorine group into the PBA moiety. As a result, the p<italic>K</italic><sub>a</sub> value of this fluorescent probe was lowered and the probe was able to recognize sugars at the physiological pH of 7.4. The sensor was found to produce two types of fluorescent signals, monomer fluorescence and dimer fluorescence, by forming a supramolecular 2:1 complex of <bold>1</bold> with glucose inside a γ-cyclodextrin (γ-CyD) cavity. Selective ratiometric sensing of glucose by the <bold>1</bold>/γ-CyD complex was achieved in water at physiological pH.</p>