N-Pyridineium-2-yl Darrow Red Analogue: Unique Near-Infrared Lysosome-Biomarker for the Detection of Cancer Cells
Dan-Dan He †, Wu Liu†, Ru Sun*†(孙如), Chen Fan‡, Yu-Jie Xu‡ and Jian-Feng Ge*†§(葛健锋)
† College of Chemistry, Chemical Engineering and Material Science, Collaborative Innovation Center of Suzhou Nano Science and Technology
‡ School of Radiation Medicine and Protection, Medicinal College, Soochow University, 199 Ren'Ai Road, Suzhou 215123, People's Republic of China
§ Jiangsu Key Laboratory of Medical Optics, Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, People's Republic of China
Anal. Chem. 2015, 87, 1499–1502
The lysosome-targetable OFF–ON type pH sensor that does not emit at pH = 4.0 is adopted for the selective detection of cancer cells, and the acidity difference of lysosomes in cancer and normal cells is verified. Three pH probes based on Darrow Red derivatives were designed and prepared that were demonstrated to be lysosome-specific biomarkers with inducible emission at 580–850 nm by the comparable in cellular imaging assays using HeLa, KB, and V79 cells. Of these, a pyridineium-2-yl Darrow Red analogue with a pKa of 2.4 was found to be a lysosome tracker for cancer cells, it is a unique pH sensor for the optical identification and distinction of cancer cells from normal cells and has potential application as a fluorescent biomaker of cancer cells in in vitro assays.