Poly(ethylene glycol) Hydrogel-Encapsulated Fluorophore−Enzyme Conjugates for Direct Detection of Organophosphorus Neurotoxins

• Published in: Analytical chemistry (Washington) Vol. 71; no. 21; pp. 4909 - 4912
• Main Authors: Russell, Ryan J, Pishko, Michael V, Simonian, Aleksandr L, Wild, James R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-11-1999
• Subjects: Aryldialkylphosphatase; Biological and medical sciences; Biotechnology; Chemistry; Enzymes; Enzymes, Immobilized - chemistry; Esterases - chemistry; Esterases - metabolism; Fluoresceins - chemistry; Fluorescence; Fundamental and applied biological sciences. Psychology; Hydrogels - chemistry; Methods. Procedures. Technologies; Neurotoxins - analysis; Organophosphorus Compounds - analysis; Others; Paraoxon - analysis; Paraoxon - chemistry; Polyethylene Glycols - chemistry; Sensitivity and Specificity; Sensors; Solutions; Various methods and equipments; Water; Encapsulation; Enzyme; Esterases; Fluorescence spectrometry; Ethylene oxide polymer; Hydrolysis; Phosphoric triester hydrolases; Analysis method; Fluorophore; Neurotoxin; Hydrolases; Organophosphorus compounds; Aryldialkylphosphatase; Hydrogel; Conjugated compound; Immobilized enzyme; Quantitative analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac990901u

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 λ = 550 in response to pH. Using spectrofluorimetry and paraoxon as a model organophosphate, paraoxon concentrations as low as 8 × 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.