Facile Fabrication of Zirconia Modified Screen‐Printed Carbon Electrodes for Electrochemical Sensing of Phosphate

We report here a facile method to immobilize zirconia nanoparticles on a disposable screen‐printed carbon electrode (designated as ZrO 2 ‐SPCE) for phosphate sensor application. Simply by ultrasonicating a bare SPCE in a ZrO 2 slurry, ZrO 2 nanoparticles can be immobilized effectively on the electrode surface as verified by surface characterization evidences. Using ferricyanide as a redox probe, an increase in the charge transfer resistance ( R ct ) of ferricyanide upon adsorption of phosphate on ZrO 2 is used for the determination of phosphate. This ZrO 2 ‐SPCE phosphate sensor shows a wide linear range up to 1 mM and a detection limit of 1.69 µM ( S / N =3). Practical applicability of the ZrO 2 ‐SPCE is demonstrated by detecting phosphate content in human blood samples.