Electropolymerization of pyrrole and immobilization of glucose oxidase in a flow system: influence of the operating conditions on analytical performance.
The in situ potentiostatic electropolymerization of pyrrole (Py) on a Pt electrode in a thin-layer amperometric cell and the entrapment of the enzyme glucose oxidase (GOx) for the determination of glucose are reported. Polypyrrole (PPy) is directly formed by continuous passage of a buffered solution of the monomer (0.4 M) and enzyme (250 U mL-1) at pH 7 at a flow rate of 0.05-0.1 mL min-1 under a constant applied potential of +0.85 V vs Ag/AgCl decreases. The electrosynthesis of PPy by injection of 500 microL of a Py + GOx solution in a carrier electrolyte consisting of 0.05 M phosphate buffer and 0.1 M KCl at pH 7.0 was also assayed. The influence of the electropolymerization conditions on the analytical response of the sensor to glucose was investigated. The analytical performance of the PPy/GOx sensor was also studied in terms of durability and storage life, as well as selectivity against electroactive species such as ascorbic acid and uric acid as a function of the thickness of the polymer film formed.
Vidal
J C
JC
Department of Analytical Chemistry, GEAS, Faculty of Sciences, University of Zaragoza, Spain.
Garcia
E
E
Castillo
J R
JR
D004563:Electrochemistry; D017022:Flow Injection Analysis; D005947:Glucose / Q000032:analysis; D005949:Glucose Oxidase; D011108:Polymers; D011199:Potentiometry; D011758:Pyrroles / Q000737:chemistry*; D012680:Sensitivity and Specificity
D011108:Polymers; D011758:Pyrroles; D005949:Glucose Oxidase; D005947:Glucose