Peroxynitrite (ONOO−), a reactive nitrogen species (RNS), engages in various cellular processes including inflammation, apoptosis, and necrosis. Therefore, the development of a powerful tool for imaging endogenous ONOO− is important with regard to revealing its underlying physiological or pathological functions. In this work, we introduced dihalogen (Cl, Br, and I) at the ortho-positions of the hydroxyl group of a dicyanoisophorone skeleton to adjust its pKa to be more suitable for bio-imaging in the physiological environments with a high signal-to-noise ratio. Based on the optimized spectral results and the requirement of biocompatibility, the fluorescent probe NIR-dCl was successfully designed and fabricated for the detection of ONOO−. Upon the addition of ONOO− in solution, an obvious NIR fluorescent signal at 680 nm was observed. Moreover, the probe NIR-dCl exhibited high selectivity for sensing ONOO−. Cell imaging results confirmed that probe NIR-dCl was capable of imaging exogenous and endogenous ONOO− in live cells. Thus, we believe that probe NIR-dCl could be an effective tool for studying biochemical processes and ONOO−-related diseases.
Bibliographical noteFunding Information:
This study was supported by grants from the National Research Foundation of Korea ( NRF ) funded by the Korean government ( MSIP ) (No. 2012R1A3A2048814 for J. Y). High-resolution mass spectrometer analysis was performed on the Synapt G2-HDMS mass spectrometer (Waters, Manchester, U.K.), which was operated on the MassLynx 4.1 software at KBSI (Korea Basic Science Institue, Ochang, Center of Research Equipment).
© 2021 Elsevier Ltd
- Cell imaging
- NIR Fluorescent probe
- pKa regulation
- Reactive nitrogen species