title: Polypyrrole-hydrogel composites for the construction of clinically important biosensors.
abstract: The present study reports on the use of p(2-hydroxyethyl methacrylate) (pHEMA) in which polypyrrole and various oxidoreductase enzymes were physically entrapped to function as a viable matrix for the construction of clinically important amperometric biosensors. Glucose oxidase, cholesterol oxidase and galactose oxidase biosensors were constructed. Electrode-supported hydrogel films were prepared by UV polymerization of the HEMA component (containing the dissolved enzyme) followed immediately by electrochemical polymerization (+0.7V vs. Ag/AgCl) of the pyrrole component within the interstitial spaces of the pre-formed hydrogel network. The optimized glucose oxidase biosensor displayed a wide linear glucose response range (5.0 x 10(-5) to 2.0 x 10(-2) M), a detection limit (3S(y/x)/sensitivity) of 25 microM and a response time of 35-40 s. The analytical recovery of glucose in serum samples ranged from 98 to 102% with mean coefficients of variation of 4.4% (within-day analyses) and 5.1% (day-to-day analyses). All three sensors displayed good stabilities when stored desiccated in the absence of buffer (>9 months).
authors.affiliation: Department of Chemistry, The University of the West Indies, St. Augustine, Trinidad and Tobago.
authors.forename: Sean
authors.initials: S
authors.lastname: Brahim
authors.forename: Dyer
authors.initials: D
authors.lastname: Narinesingh
authors.forename: Anthony
authors.initials: A
authors.lastname: Guiseppi-Elie
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis*; D002138:Calibration; D002789:Cholesterol Oxidase / Q000378:metabolism*; D004058:Diffusion; D005692:Galactose Oxidase / Q000378:metabolism*; D005949:Glucose Oxidase / Q000378:metabolism*; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D006863:Hydrogen-Ion Concentration; D011108:Polymers; D011758:Pyrroles; D013696:Temperature
chemical_list: D001786:Blood Glucose; D011108:Polymers; D011758:Pyrroles; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; C067635:polypyrrole; D005949:Glucose Oxidase; D002789:Cholesterol Oxidase; D005692:Galactose Oxidase