Investigation of Electrochemical Properties of Keggin-type Phosphotungstic Acid/2-Amino Pyridine Electropolymerized Modified Electrode and Its Electrocatalysis Towards Vitamin B2

KeyWord:phosphotungstic acid/2-amino pyridine electropolymerized film  vitamin B2  electrocatalysis

Abstract:

      A novel Keggin-type phosphotungstic acid H7£ÛP(W2O7)6£Ý/2-amino pyridine electropolymerization(PW/PAP) modified glassy carbon electrode was fabricated by electrodepositing H7£ÛP(W2O7)6£Ý onto 2 amino pyridine electro polymerized glassy carbon electrode.The electrochemical behaviors of PW/PAP modified electrode were investigated by cyclic voltammetry.It is found that there are three redox peaks appeared in the potential range from -0.8 V to 0.2 V in BR buffer solution.The modified electrode showed a good electrocatalysis towards the electro-oxidation of vitamin B2(VB2).The electrochemical behavior of VB2 was surface-controlled.The electron transfer coefficient and rate constant were calculated to be 0.357 and 0.042 s-1£¬respectively£¬indicating that the electrochemical reaction of VB2 was a quasi-reversible process.Under the optimal conditions£¬there was a good linear relationship between the peak currents and VB2 concentrations in the concentration range of 2.4¡Á10-6-1.0¡Á10-4mol/L and 1.0¡Á10-4-5.5¡Á10-4 mol/L£¬with a detection limit of 1.4¡Á10-6 mol/L.The composite electrode had good stability and reproducibility£¬and was used in the determination of VB2 in composite vitamin tablets with satisfactory results.