Non-enzymatic electrochemical sensing of glucose and hydrogen peroxide using a bis(acetylacetonato) oxovanadium(IV) complex modified gold electrode

A non-enzymatic electrochemical sensor,bis(acetylacetonato) oxovanadium(IV) complex, [VO(acac)(2)], fabricated on a self-assembled 4-(pyridine-4'-amido)thiophenol (PATP) monolayer modified gold electrode, was developed for the detection of glucose and hydrogen peroxide (H2O2) at neutral pH. The modified electrode was characterized by electrochemical and microscopic techniques. The non-enzymatic sensor exhibited a remarkable catalytic performance for glucose oxidation and H2O2 reduction. Chronoamperometry was used for the electrochemical determination of glucose and H2O2. The non-enzymatic sensing of glucose was realized with a linear response range from 0.001 to 0.5 mM with a detection limit of 0.1 mu M (S/N = 3). The sensor also has a good performance for the electrocatalytic reduction of H2O2 with a linear response range from 0.02 to 0.9 mM with a detection limit of 0.03 mu M (S/N = 3). In addition, [VO(acac)(2)]-PATP-Au showed a good selectivity for glucose and H2O2 detection in the presence of potential interfering agents such as ascorbic acid, uric acid, L-dopa, L-cysteine and different ions like Na+, K+, Cl- etc. The kinetic parameters such as the electron transfer coefficient and the catalytic reaction rate constant were also determined for glucose and H2O2. Finally, the modified electrode was used to achieve quantitative detection of glucose and H2O2 in blood and milk, respectively for practical applications.