AUTHOR=Pham Thanh Chung , Nguyen Van-Nghia , Choi Yeonghwan , Kim Dongwon , Jung Ok-Sang , Lee Dong Joon , Kim Hak Jun , Lee Myung Won , Yoon Juyoung , Kim Hwan Myung , Lee Songyi 

TITLE=Hypochlorite-Activated Fluorescence Emission and Antibacterial Activities of Imidazole Derivatives for Biological Applications

JOURNAL=Frontiers in Chemistry

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2021.713078

DOI=10.3389/fchem.2021.713078

ISSN=2296-2646

ABSTRACT=<p>The ability to detect hypochlorite (HOCl/ClO<sup>−</sup>) <italic>in vivo</italic> is of great importance to identify and visualize infection. Here, we report the use of imidazoline-2-thione (<bold>R</bold><sub><bold>1</bold></sub><bold>SR</bold><sub><bold>2</bold></sub>) probes, which act to both sense ClO<sup>−</sup> and kill bacteria. The N<sub>2</sub>C=S moieties can recognize ClO<sup>−</sup> among various typical reactive oxygen species (ROS) and turn into imidazolium moieties (<bold>R</bold><sub><bold>1</bold></sub><bold>IR</bold><sub><bold>2</bold></sub>) <italic>via</italic> desulfurization. This was observed through UV–vis absorption and fluorescence emission spectroscopy, with a high fluorescence emission quantum yield (Փ<sub>F</sub> = 43–99%) and large Stokes shift (∆v∼115 nm). Furthermore, the <bold>DIM</bold> probe, which was prepared by treating the <bold>DSM</bold> probe with ClO<sup>−</sup>, also displayed antibacterial efficacy toward not only <italic>Escherichia coli</italic> (<italic>E. coli</italic>) and <italic>Staphylococcus aureus</italic> (<italic>S. aureus</italic>) but also methicillin-resistant <italic>Staphylococcus aureus</italic> (MRSA) and extended-spectrum ß-lactamase–producing <italic>Escherichia coli</italic> (ESBL-EC), that is, antibiotic-resistant bacteria. These results suggest that the <bold>DSM</bold> probe has great potential to carry out the dual roles of a fluorogenic probe and killer of bacteria.</p>