Nanostructured Polyoxometalate-Based Heterogeneous Electrode Materials for Electrochemical Sensing of Glucose

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