title: pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.
abstract: Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing.
authors.affiliation: Division of Liberal Arts, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama, 350-0394, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Adachi
authors.affiliation: Division of Science, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama, 350-0394, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Division of Science, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama, 350-0394, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Sekiguchi
authors.affiliation: Division of Science, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama, 350-0394, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sugiyama
authors.affiliation: Division of Science, School of Science and Engineering, Tokyo Denki University, Hatoyama, Hiki-gun, Saitama, 350-0394, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Sugeno
mesh_terms: D005453:Fluorescence; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D011726:Pyridinium Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011108:Polymers; D011725:Pyridines; D011726:Pyridinium Compounds; C547601:poly(pyridinium phenylene); C023666:pyridine
keywords: chemical sensor; conjugated polymers; fluorescence color change; pH sensing; pyridine units