A potentiometric phosphate biosensor based on entrapment of pyruvate oxidase in a polypyrrole film

Abstract

A polypyrrole based potentiometric phosphate biosensor has been fabricated by entrapment of pyruvate oxidase in a polypyrrole film. The optimum conditions for the fabrication of biosensors were 0.3 M pyrrole, a polymerization time of 120 s, an applied current density of 0.05 mA cm⁻² and 2 U mL⁻¹ of pyruvate oxidase. Under these conditions, the polypyrrole–pyruvate oxidase (PPy–PyOx) biosensor enabled the achievement of a minimum detectable concentration of 3 μM phosphate, a linear concentration range of 15–400 μM (r² = 0.980). The biosensor was successfully applied to the detection of phosphate in lake water samples with excellent recoveries ranging from 99–100%.