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A Bienzyme Electrode (Alkaline Phosphatase−Polyphenol Oxidase) for the Amperometric Determination of Phosphate
- Source :
- Analytical Chemistry. 70:3952-3956
- Publication Year :
- 1998
- Publisher :
- American Chemical Society (ACS), 1998.
-
Abstract
- The electropolymerization of an alkaline phosphatase (AP)−amphiphilic pyrrole ammonium mixture previously adsorbed on the electrode surface provides efficient entrapment of AP in a polypyrrole film. The resulting biosensor was applied to the detection of phenyl phosphate via amperometric oxidation at 0.6 V vs SCE of the enzymically generated phenol. The sensitivity and detection limit of the biosensor were 862 μA M-1 cm-2 and 20 μM, respectively. The co-immobilization of polyphenol oxidase and AP leads to a bienzyme electrode for the determination of phenyl phosphate on the basis of amperometric detection of the enzymically generated o-quinone at −0.2 V. An amplification factor of 9.7 was calculated as the ratio of the bienzyme to monoenzyme electrode sensitivities. In the presence of 5 mM MgCl2, the sensitivity and detection limit of the biosensor for phenyl phosphate were 36.82 mA M-1 cm-2 and 0.2 μM, respectively. Phosphate competitively inhibited the hydrolysis of phenyl phosphate. Consequently, its d...
Details
- ISSN :
- 15206882 and 00032700
- Volume :
- 70
- Database :
- OpenAIRE
- Journal :
- Analytical Chemistry
- Accession number :
- edsair.doi...........896d50809c38b56cd82f832113409cfe