Non-Enzymatic Electrochemical Detection of Glucose by Mixed-Valence Cobalt Containing Keggin Polyoxometalate/Multi-Walled Carbon Nanotube Composite

In this work, a non-enzymatic electrochemical sensor platform was developed for catalyze of glucose using graphite electrode modified with Keggin type K7[CoIIICoII(H2O)W11O39].15H2O (Co-POM) and multi-walled carbon nanotube (MWCNT) composite. The Keggin type Co-POM composing of a unique mixed-valence Co(III) and Co(II) structures was confined in a matrix of MWCNT on graphite electrodes to improve the electron transfers. Cyclic voltammetry (CV) and amperometric measurements were performed to investigate the electroanalytical performance of the Co-POM/MWCNT composite for direct electrochemical oxidation of glucose. The proposed this non-enzymatic sensor platform showed a wide linear range from 0.1 mM to 10.0 mM (R = 0.9937) for detection of glucose. Besides it exhibited low detection limit of 1.21 μM and fast response time of 6s and high sensitivity of 256.4 μA mM−1 cm−2. The results demonstrated that the proposed Co-POM/MWCNT based sensor platform has a high sensitivity, good stability, excellent selectivity, an enhanced electrocatalytic property and acceptable recovery. Therefore, Co-POM/MWCNT based sensor platform is promising potential application for the development of non-enzymatic sensor and catalyst applications.