title: A Novel Water-soluble Ratiometric Fluorescent Probe Based on FRET for Sensing Lysosomal pH.
abstract: A new ratiometric fluorescent probe based on Förster resonance energy transfer (FRET) for sensing lysosomal pH has been developed. The probe (RMPM) was composed of imidazo[1,5-α]pyridine quaternary ammonium salt fluorophore as the FRET donor and the rhodamine moiety as the FRET acceptor. It's the first time to report that imidazo[1,5-α]pyridine quaternary ammonium salt acts as the FRET donor. The ratio of fluorescence intensity of the probe at two wavelengths (I424/I581) changed significantly and responded linearly toward minor pH changes in the range of 5.4-6.6. It should be noted that it's rare to report that a ratiometric pH probe could detect so weak acidic pH with pKa = 6.31. In addition, probe RMPM exhibited excellent water-solubility, fast-response, all-right selectivity and brilliant reversibility. Moreover, RMPM has been successfully applied to sensing lysosomal pH in HeLa cells and has low cytotoxicity.
authors.affiliation: School of Chemical Engineering, Taishan Medical University, Tai'an, 271000, China.|Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
authors.forename: Guang-Jie
authors.initials: GJ
authors.lastname: Song
authors.affiliation: Institute of Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, China.|School of Life Science, Taishan Medical University, Tai'an, 271000, China.
authors.forename: Su-Yun
authors.initials: SY
authors.lastname: Bai
authors.affiliation: School of Chemical Engineering, Taishan Medical University, Tai'an, 271000, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Luo
authors.affiliation: School of Chemical Engineering, Taishan Medical University, Tai'an, 271000, China. xqcao@tsmc.edu.cn.
authors.forename: Xiao-Qun
authors.initials: XQ
authors.lastname: Cao
authors.affiliation: Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China. bxzhao@sdu.edu.cn.
authors.forename: Bao-Xiang
authors.initials: BX
authors.lastname: Zhao
mesh_terms: D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted; D008247:Lysosomes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014867:Water / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D000644:Quaternary Ammonium Compounds; D014867:Water
keywords: Image; Imidazo[1,5-α]pyridine quaternary ammonium salt; Lysosomal pH; Ratiometric fluorescent probe; Water-solubility