title: Nitric oxide-releasing xerogel-based fiber-optic pH sensors.
abstract: A xerogel-based optical pH sensor capable of releasing low levels of nitric oxide (NO) and measuring changes in solution pH is reported. Through simple dip-coating procedures, aminoalkoxysilane-based xerogel films modified with N-diazeniumdiolate NO donor precursors and the fluorescent pH indicator seminaphthorhodamine-1 carboxylate (SNARF-1) were sequentially deposited onto optical fibers. The resulting sensors were characterized by fast and linear response to pH throughout the physiological range (pH 7.0-7.8). Real-time chemiluminescence measurements confirmed that the presence of the overlying SNARF-1-containing TMOS layer did not have an inhibitory effect on N-diazeniumdiolate formation or NO release, and the NO-releasing coatings were capable of maintaining NO fluxes >0.4 pmol/cm(2) s up to 16 h. In vitro blood compatibility studies using porcine platelets confirmed the expected thromboresistivity of the NO-releasing xerogel coatings.
authors.affiliation: Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
authors.forename: Kevin P
authors.initials: KP
authors.lastname: Dobmeier
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Charville
authors.forename: Mark H
authors.initials: MH
authors.lastname: Schoenfisch
mesh_terms: D000818:Animals; D001578:Benzopyrans / Q000737:chemistry; D001792:Blood Platelets / Q000166:cytology / Q000648:ultrastructure; D002448:Cell Adhesion; D005336:Fiber Optic Technology; D005456:Fluorescent Dyes / Q000737:chemistry; D005782:Gels; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D009284:Naphthols / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry*; D055100:Optical Fibers; D015203:Reproducibility of Results; D012235:Rhodamines / Q000737:chemistry; D012680:Sensitivity and Specificity; D013552:Swine
chemical_list: D001578:Benzopyrans; D005456:Fluorescent Dyes; D005782:Gels; D009284:Naphthols; D012235:Rhodamines; C091666:seminaphthorhodaminefluoride; D009569:Nitric Oxide