Frontiers in Chemistry (Jul 2021)

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,
  • Hwan Myung Kim,
  • Songyi Lee,
  • Songyi Lee

DOI
https://doi.org/10.3389/fchem.2021.713078
Journal volume & issue
Vol. 9

Abstract

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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 (R1SR2) 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 (R1IR2) via desulfurization. This was observed through UV–vis absorption and fluorescence emission spectroscopy, with a high fluorescence emission quantum yield (ՓF = 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.

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