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

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

doi:10.3389/fchem.2021.713078

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

Front Chem. 2021 Jul 12:9:713078. doi: 10.3389/fchem.2021.713078. eCollection 2021.

Authors

Thanh Chung Pham¹, Van-Nghia Nguyen², Yeonghwan Choi¹, Dongwon Kim³, Ok-Sang Jung³, Dong Joon Lee⁴, Hak Jun Kim⁵, Myung Won Lee⁵, Juyoung Yoon², Hwan Myung Kim^{4

6}, Songyi Lee^{1

5}

Affiliations

¹ Industry 4.0 Convergence Bionics Engineering, Pukyong National University, Busan, South Korea.
² Department of Chemistry and Nanoscience, Ewha Womans University, Seoul, South Korea.
³ Department of Chemistry, Pusan National University, Busan, South Korea.
⁴ Department of Energy Systems Research, Ajou University, Suwon, South Korea.
⁵ Department of Chemistry, Pukyong National University, Busan, South Korea.
⁶ Department of Chemistry, Ajou University, Suwon, South Korea.

Abstract

The ability to detect hypochlorite (HOCl/ClO^-) in vivo is of great importance to identify and visualize infection. Here, we report the use of imidazoline-2-thione (R ₁ SR ₂ ) probes, which act to both sense ClO^- and kill bacteria. The N₂C=S moieties can recognize ClO^- among various typical reactive oxygen species (ROS) and turn into imidazolium moieties (R ₁ IR ₂ ) via desulfurization. This was observed through UV-vis absorption and fluorescence emission spectroscopy, with a high fluorescence emission quantum yield (Փ_F = 43-99%) and large Stokes shift (∆v∼115 nm). Furthermore, the DIM probe, which was prepared by treating the DSM probe with ClO^-, also displayed antibacterial efficacy toward not only Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) but also methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC), that is, antibiotic-resistant bacteria. These results suggest that the DSM probe has great potential to carry out the dual roles of a fluorogenic probe and killer of bacteria.

Keywords: antibacterial effect; fluorescent sensor; fluorogenic probe; hypochlorite sensor; probe–killer.