title: Pyrene functionalized molecular beacon with pH-sensitive i-motif in a loop.
abstract: In this work, we present a spectral characterization of pH-sensitive system, which combines the i-motif properties with the spatially sensitive fluorescence signal of pyrene molecules attached to hairpin ends. The excimer production (fluorescence max. ∼480 nm) by pyrene labels at the ends of the molecular beacon is driven by pH-dependent i-motif formation in the loop. To illustrate the performance and reversible work of our systems, we performed the experiments with repeatedly pH cycling between pH values of 7.5±0.3 and 6.5±0.3. The sensor gives analytical response in excimer-monomer switching mode in narrow pH range (1.5 pH units) and exhibits high pH resolution (0.1 pH unit).
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland. Electronic address: aniojka@amu.edu.pl.
authors.forename: Anna
authors.initials: A
authors.lastname: Dembska
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland.
authors.forename: Bernard
authors.initials: B
authors.lastname: Juskowiak
mesh_terms: D001483:Base Sequence; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D011119:Polynucleotides / Q000737:chemistry*; D011721:Pyrenes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D011119:Polynucleotides; D011721:Pyrenes; C030984:pyrene
keywords: Excimer fluorescence; Molecular beacon; i-motif; pH