title: Poly(ethylene glycol) hydrogel-encapsulated fluorophore-enzyme conjugates for direct detection of organophosphorus neurotoxins.
abstract: A simple approach is described for preparing poly-(ethylene glycol) hydrogel materials with encapsulated seminapthofluorescein (SNAFL)-organophosphorus hydrolase enzyme conjugates. Direct determination of enzyme-catalyzed neurotoxin hydrolysis is provided by the self-referencing, pH-sensitive dye SNAFL-1, whose emission spectrum changes at lambda = 550 in response to pH. Using spectrofluorimetry and paraoxon as a model organophosphate, paraoxon concentrations as low as 8 x 10(-7) M could be readily detected. On the basis of the signal-to-noise ratio, a detection limit of 16 nM was determined. The materials demonstrated high stability against enzyme-denaturing, leaching, and photobleaching when stored under ambient conditions.
authors.affiliation: Department of Chemical Engineering, Texas A&M University, College Station 77843-3122, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Russell
authors.forename: M V
authors.initials: MV
authors.lastname: Pishko
authors.forename: A L
authors.initials: AL
authors.lastname: Simonian
authors.forename: J R
authors.initials: JR
authors.lastname: Wild
mesh_terms: D043303:Aryldialkylphosphatase; D004800:Enzymes, Immobilized / Q000737:chemistry; D004950:Esterases / Q000737:chemistry* / Q000378:metabolism; D005452:Fluoresceins / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry; D009498:Neurotoxins / Q000032:analysis*; D009943:Organophosphorus Compounds / Q000032:analysis*; D010261:Paraoxon / Q000032:analysis / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D012680:Sensitivity and Specificity; D012996:Solutions; D014867:Water
chemical_list: D004800:Enzymes, Immobilized; D005452:Fluoresceins; D020100:Hydrogels; D009498:Neurotoxins; D009943:Organophosphorus Compounds; D012996:Solutions; C401959:seminaphthofluorescein; D014867:Water; D011092:Polyethylene Glycols; D004950:Esterases; D043303:Aryldialkylphosphatase; D010261:Paraoxon