Polypyrrole based amperometric and potentiometric phosphate biosensors: a comparative study B.

Area of Science:

• Electrochemistry
• Biosensor technology
• Materials science

Background:

• Phosphate detection is crucial for environmental monitoring and biological studies.
• Electrochemical biosensors offer sensitive and selective analyte detection.
• Polypyrrole (PPy) is a versatile material for biosensor fabrication due to its conductivity and biocompatibility.

Purpose of the Study:

• To develop and compare two electrochemical biosensors for phosphate determination.
• To investigate the co-immobilization of Purine nucleoside phosphorylase (PNP) and xanthine oxidase (XOD) within polypyrrole films.
• To evaluate the performance of potentiometric and amperometric phosphate biosensors.

Main Methods:

• Co-immobilization of PNP and XOD into polypyrrole films via galvanostatic polymerization.
• Fabrication of an amperometric biosensor using PPy-PNP-XOD-Fe(CN)(6)(4-).
• Construction of a potentiometric bi-layer biosensor (PPy-NO(3)/BSA-GLA-PNP-XOD) with an inner PPy-NO(3) layer and an outer PNP-XOD layer.

Main Results:

• The amperometric biosensor achieved a minimum detectable concentration of 10 μM and a linear range of 0.1-1 mM.
• The potentiometric biosensor exhibited a minimum detectable concentration of 20.0 μM and a linear range of 20-200 μM.
• Both biosensors showed minimal interference from uric and ascorbic acids, enabling phosphate analysis in real water samples.

Conclusions:

• Both developed electrochemical biosensors are effective for phosphate detection.
• The amperometric biosensor demonstrates superior sensitivity and a broader linear range compared to the potentiometric one.
• The biosensors exhibit good stability and selectivity, making them suitable for practical applications in phosphate monitoring.