title: Bispyrene-fluorescein hybrid based FRET cassette: a convenient platform toward ratiometric time-resolved probe for bioanalytical applications.
abstract: Pyrene excimer possesses a large Stokes shift and long fluorescence lifetime and has been widely applied in developing time-resolved biosensing systems to solve the autofluorescence interference problems in biological samples. However, only a few of pyrene excimer-based small molecular probes have been reported so far. Ratiometric probes, on the other hand, can eliminate interferences from environmental factors such as instrumental efficiency and environmental conditions by a built-in correction of the dual emission bands but are ineffective for endogenous autofluorescence in biosystems. In this work, by combining the advantages of time-resolved fluorescence technique with ratiometric probe, we reported a bispyrene-fluorescein hybrid FRET cassette (PF) as a novel ratiometric time-resolved sensing platform for bioanalytical applications, with pH chosen as a biorelated target. The probe PF showed a fast, highly selective, and reversible ratiometric fluorescence response to pH in a wide range from 3.0 to 10.0 in buffered solution. By employing time-resolved fluorescence technique, the pH-induced fluorescence signal of probe PF can be well-discriminated from biological autofluorescence background, which enables us to detect pH in a range of 4.0-8.0 in cell media within a few seconds. It has also been preliminarily applied for ratiometric quantitative monitoring of pH changes in living cells with satisfying results. Since many fluorescein-based fluorescence probes have been developed, our strategy might find wide applications in design ratiometric time-resolved probes for detection of various biorelated targets.
authors.affiliation: Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, College of Biology, Hunan University , Changsha 410082, China.
authors.forename: Yong-Xiang
authors.initials: YX
authors.lastname: Wu
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Zhang
authors.forename: Jun-Bin
authors.initials: JB
authors.lastname: Li
authors.forename: Cui-Cui
authors.initials: CC
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Liang
authors.forename: Guo-Jiang
authors.initials: GJ
authors.lastname: Mao
authors.forename: Li-Yi
authors.initials: LY
authors.lastname: Zhou
authors.forename: Weihong
authors.initials: W
authors.lastname: Tan
authors.forename: Ru-Qin
authors.initials: RQ
authors.lastname: Yu
mesh_terms: D001681:Biological Assay / Q000295:instrumentation / Q000379:methods*; D019793:Fluorescein / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D015394:Molecular Structure; D011721:Pyrenes / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D011721:Pyrenes; C030984:pyrene; D019793:Fluorescein