“…10 The powerful ionic-coordinative interaction between zirconium ions and phosphate groups can be used in many cases, such as the formation and functionalization of thin films on solid substrates, such as metals and non-metallic materials, as well as the creation of self-supporting supermolecular arrays for various purposes. 11 According to early electrochemical studies, based on the strong absorption of phosphate ion on the surface of the Zr(IV) immobilized on goldmercaptopropionic acid self-assembledmonolayer (Au-MPA-Zr(IV) SAM) electrode mentioned in our previous study, a simple, inexpensive and fast analytical method for measuring phosphate ion in a human serum sample is presented. 12 In spite of its unique features, its simplicity, low price and excellent detection limit, Zr/rGO-PGE has not been used up until now for the electrochemical determination of phosphate.…”