Amperometric detection of phenolic compounds by polypyrrole-based composite carbon paste electrodes.
This contribution describes new composite carbon paste electrodes (CPEs) for the determination of phenolic compounds. The composite CPEs were prepared by in situ generation of polypyrrole (PPy) within a paste containing the enzyme polyphenol oxidase (PPO). The best paste composition (enzyme/pyrrole monomer/carbon particles/Nujol) was determined for a model enzyme, glucose oxidase (GOx) according to the enzymatic activity of the resulting electrodes and to the enzyme leakage from the paste during storage in phosphate buffer. The in situ electrogenerated PPy improves the enzyme immobilisation within the paste since practically no enzyme was lost in solution after 72 h of immersion. Moreover, the enzyme activity remains particularly stable under storage since the biocomposite structure conserves 80% of its activity after 1 month of storage. Following the optimisation of the paste composition, PPO-based carbon paste biosensors were prepared and presented excellent analytical properties toward catechol detection with a sensitivity of 4.7 A M(-1) cm(-2) and a response time lower than 20 s. The resulting biosensors were applied to the determination of polyphenolic compounds (e.g., epicatechin and ferulic acid).
Mailley
Pascal
P
CREAB group, Laboratoire des Structures et Propriétés des Architectures Moléculaires UMR 5819 CNRS-CEA-Université Joseph Fourier Grenoble 1, DRFMC/SI3M/CREAB, CEA 17 avenue des Martyrs 38054 Grenoble cedex 9, France. pmailley@cea.fr
Cummings
Edward A
EA
Mailley
Sophie
S
Cosnier
Serge
S
Eggins
Brian R
BR
McAdams
Eric
E
D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D044948:Flavonols / Q000032:analysis / Q000737:chemistry; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D008420:Manufactured Materials / Q000032:analysis; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D009824:Ointments; D010636:Phenols / Q000032:analysis* / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D013499:Surface Properties
D004800:Enzymes, Immobilized; D044948:Flavonols; D009824:Ointments; D010636:Phenols; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D002244:Carbon; D005949:Glucose Oxidase; D014442:Monophenol Monooxygenase; D005947:Glucose