A mitochondria-targeted ratiometric fluorescent probe to monitor endogenously generated sulfur dioxide derivatives in living cells.
Sulfur dioxide (SO2) can be endogenously produced by enzymes in mitochondria during oxidation of H2S or sulphur-containing amino acids, and plays important roles in several physiological processes. However, the design and synthesis of fluorescent probes which can detect mitochondrial SO2 and its derivatives in living cells still remain unresolved. Herein, we report the preparation of a lipophilic cationic dye 1 (Mito-Ratio-SO2), which targets the mitochondria in living cells and is sensitive to the presence of SO2 derivatives. The ratiometric probe Mito-Ratio-SO2 displays a 170 nm blue-shift in emission with two well-resolved emission bands upon addition of sulfite. Mechanistic studies indicate that three probe-SO2 adducts coexist after reaction, as supported by liquid chromatography and density function theory investigations. Importantly, the ratiometric probe is highly selective for sulfite over other bio-species including H2S. Fluorescence co-localization studies indicate that the probe localizes solely in the mitochondria of HeLa cells. Last but not least, fluorescent imaging of HeLa cells successfully demonstrates the detection of intrinsically generated intracellular SO2 derivatives in living cells.
Department of Chemistry & Med Chem Program, National University of Singapore, 117543, Singapore; Singapore Peking Oxford Research Enterprise (SPORE), Environmental Research Institute (NERI), 5A Engineering Drive 1, #02-01, 117411, Singapore.
Wang
W
Xu
Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 138667, Singapore.
Chai Lean
CL
Teoh
Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 138667, Singapore.
Juanjuan
J
Peng
Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 138667, Singapore.
Dongdong
D
Su
Department of Chemistry & Med Chem Program, National University of Singapore, 117543, Singapore; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan, 410082, PR China. Electronic address: lyuan@hnu.edu.cn.
Lin
L
Yuan
Department of Chemistry & Med Chem Program, National University of Singapore, 117543, Singapore; Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), 138667, Singapore. Electronic address: chmcyt@nus.edu.sg.
Young-Tae
YT
Chang
D015374:Biosensing Techniques; D002412:Cations; D003374:Coumarins / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006862:Hydrogen Sulfide / Q000737:chemistry; D007211:Indoles / Q000737:chemistry; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000737:chemistry*; D013447:Sulfites / Q000737:chemistry; D013458:Sulfur Dioxide / Q000737:chemistry*
D002412:Cations; D003374:Coumarins; D005456:Fluorescent Dyes; D007211:Indoles; C000604945:Mito-Ratio-SO2; D013447:Sulfites; D013458:Sulfur Dioxide; D006862:Hydrogen Sulfide
Endogenous sulfur dioxide; Intramolecular charge transfer; Living cell imaging; Mitochondria; Ratiometric fluorescent probe