Amperometric biosensor for hypoxanthine based on immobilized xanthine oxidase on iron (III) meso-tetraphenylporphyrin nanoparticles modified glassy carbon electrode

The preparation and performance of hypoxanthine (Hx) electrochemical biosensor, which was based on iron (III) meso-tetraphenylporphyrin (FeTPP) nanoparticles (NPs), is reported in this work. FeTPP NPs prepared by mixing solvent techniques with diameters ca. 25-45 nm and were used as a mediator. The XOD/FeTPPNP/GC electrode exhibited good amperometric signal for Hx. Based on the consumption of dissolved oxygen during the oxidation process of Hx catalyzed by the immobilized XOD, the biosensor could detect the concentration of Hx up to 0.34 mM with a detection limit of 1.0 μM. The usefulness of this biosensor for the analysis of real sample was also demonstrated by determining Hx in rat brain dialysate coupled with microdialysis.