title: Determination of intracellular pH using sensitive, clickable fluorescent probes.
abstract: We synthesized and evaluated a series of acidic fluorescent pH probes exhibiting robust pH dependence, high sensitivity and photostability, and excellent cell membrane permeability. Titration analyses indicated that probe 3 could increase its fluorescence intensity 800-fold between pH 8.0 and 4.1. Additionally, its pK(a) value is optimal for intracellular probing of acidic organelles. Fluorescent imaging of HepG2 and Hela cells further revealed that probe 3 demonstrates outstanding capacity for monitoring of intracellular [H(+)] levels. The easily accessible terminal alkyne/azido function groups of these probes offer the possibility of rapidly constructing sensor molecule libraries using 'click' chemistry.
authors.affiliation: Department of Chemistry, Michigan Technological University, Houghton, MI 49931, USA.
authors.forename: Nazmiye B
authors.initials: NB
authors.lastname: Yapici
authors.forename: Srinivas Rao
authors.initials: SR
authors.lastname: Mandalapu
authors.forename: Teng-Leong
authors.initials: TL
authors.lastname: Chew
authors.forename: Satya
authors.initials: S
authors.lastname: Khuon
authors.forename: Lanrong
authors.initials: L
authors.lastname: Bi
mesh_terms: D000143:Acids; D015374:Biosensing Techniques; D002463:Cell Membrane Permeability; D003593:Cytoplasm / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D015388:Organelles / Q000737:chemistry; D011522:Protons; D012235:Rhodamines / Q000138:chemical synthesis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D000143:Acids; D005456:Fluorescent Dyes; D007769:Lactams; D011522:Protons; D012235:Rhodamines