Amperometric carbon paste enzyme electrodes with Fe3O4 nanoparticles and 1,4-Benzoquinone for glucose determination

Two new amperometric carbon paste enzyme electrodes including Fe3O4 nanoparticles with and without 1,4-benzoquinone were developed for glucose determination. Electron transfer properties of unmodified and Fe3O4 nanoparticles and/or 1,4-benzoquinone modified carbon paste electrodes were investigated in 0.1 M KCl support electrolyte containing Fe(CN)(6)(3-/4-) as redox probe by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Fe3O4 nanoparticles increased electron transfer at solution/electrode interface. The parameters affecting the analytical performance of the enzyme electrode have been investigated in detail and optimized for Fe3O4 nanoparticle modified enzyme electrode (Fe3O4-CPEE). Fe3O4 nanoparticles and 1,4-benzoquinone modified enzyme electrode (BQ-Fe3O4-CPEE) exhibited linear response from 1.9 x 10(-7) M to 3.7 x 10(-6) M, from 7.2 x 10(-6) M to 1.5 x 10(-4) M and from 1.3 x 10(-3) M to 1.2 x 10(-2) M with an excellent detection limit of 1.9 x 10(-8) M. BQ-Fe3O4-CPEE was used for determination of glucose in serum samples and results were in good agreement with those obtained by spectrophotometric method.