title: Conjugated Polyelectrolytes with Imidazolium Solubilizing Groups. Properties and Application to Photodynamic Inactivation of Bacteria.
abstract: This article reports an investigation of the photophysical properties and the light- and dark-biocidal activity of two poly(phenyleneethynylene) (PPE)-based conjugated polyelectrolytes (CPEs) bearing cationic imidazolium solubilizing groups. The two polymers feature the same PPE-type backbone, but they differ in the frequency of imidazoliums on the chains: PIM-4 features two imidazolium units on every phenylene repeat, whereas PIM-2 contains two imidazolium units on every other phenylene unit. Both polymers are very soluble in water and polar organic solvents, but their propensity to aggregate in water differs with the density of the imidazolium units. The polymers are highly fluorescent, and they exhibit the amplified quenching effect when exposed to a low concentration of anionic electron-acceptor anthraquinone disulfonate. The CPEs are also quenched by a relatively low concentration of pyrophosphate by an aggregation-induced quenching mechanism. The biocidal activity of the cationic imidazolium CPEs was studied against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria in the dark and under blue-light illumination. Both polymers are effective biocides, exhibiting greater than 3 log kill with 30-60 min of light exposure at concentrations of ≤10 μg mL(-1).
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611-7200, United States.
authors.forename: Anand
authors.initials: A
authors.lastname: Parthasarathy
authors.affiliation: Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico , Albuquerque, New Mexico 87131-1341, United States.
authors.forename: Harry C
authors.initials: HC
authors.lastname: Pappas
authors.affiliation: Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico , Albuquerque, New Mexico 87131-1341, United States.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Hill
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611-7200, United States.
authors.forename: Yun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Chemical and Biological Engineering and Center for Biomedical Engineering, University of New Mexico , Albuquerque, New Mexico 87131-1341, United States.
authors.forename: David G
authors.initials: DG
authors.lastname: Whitten
authors.affiliation: Department of Chemistry, University of Florida , Gainesville, Florida 32611-7200, United States.
authors.forename: Kirk S
authors.initials: KS
authors.lastname: Schanze
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D004573:Electrolytes / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D007093:Imidazoles / Q000737:chemistry / Q000494:pharmacology*; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D004573:Electrolytes; D007093:Imidazoles; D011108:Polymers
keywords: antimicrobial polymers; biocides; conjugated polyelectrolytes; ionic liquids; singlet oxygen; triplet state