Phosphate biosensor based on polyelectrolytestabilized pyruvate oxidase

In this work the development of a pyruvate oxidase-based phosphate biosensor is illustrated. The use of polyelectrolyte stabilized recombinant pyruvate oxidase in conjunction with a porous conductive carbon results in the development of a simple, reproducible and stable phosphate biosensor. The polyelectrolyte diethylaminoethyl-dextran or DNA was used as the enzyme stabilizer, and the resulting enzyme-polyelectrolyte complexes were physically adsorbed into the transducer, a highly porous and conductive carbon electrode, for the construction of the biosensor. The optimized biosensor exhibits high operational (67% remaining activity after 220h) and storage (49% remaining activity after 24 weeks) stability, and very good sensor-to-sensor reproducibility. The optimized phosphate biosensor was used for the measurement of the phosphate ion activity in serum.