Nanostructured\nPolyoxometalate-Based Heterogeneous\nElectrode Materials for Electrochemical Sensing of Glucose

Abstract

We exploited a tactic to obtain a low-cost, high-efficiency,\npollution-free,\nand stable nonenzymatic polyoxometalate-based heterogeneous electrode\nmaterial for electrochemical sensing of glucose. It is first followed\nby the countercation exchange of K₂Na₈[Cu₄(H₂O)₂(PW₉O₃₄)₂] (<b>CuPOM</b>) using cesium chloride to prepare an\ninsoluble <b>CuPOM</b> (<b>Cs-CuPOM</b>), which exhibits\na uniform and perfect claviform shape with smooth surface. Further,\nit was mixed with graphite powder to prepare <b>Cs-CuPOM-</b>modified carbon paste electrode (<b>Cs-CuPOM/CPE</b>) with\nthe <b>Cs-CuPOM</b> content between 15% and 50% in weight. This\nobtained electrode material <b>Cs-CuPOM</b> shows a better electrochemical\nsensor activity than <b>Cs-MnPOM</b>, <b>Cs-FePOM,</b> and other reported POM-based electrode materials for glucose oxidation\non account of their quicker electron transfer kinetics, which also\nexhibits conspicuous characteristics with a wide linear range of 5–1500\nμM. It also possesses a high sensitivity of 16.3 A M^–1 cm^–2 and a low limit of detection (LOD) of 0.99\n× 10^–6 M at the signal-to-noise ratio of 3.\nThe conspicuous sensing feature, low cost, and liable synthetic method\ncan make <b>Cs-CuPOM</b> a promising candidate for the exploitation\nof a preeminent glucose sensor.