Amperometric carbon paste enzyme electrodes with Fe3O4nanoparticles and 1,4-Benzoquinone for glucose determination

Abstract

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 × 10^‐7 M to 3.7 × 10^‐6 M, from 7.2 × 10^‐6 M to 1.5 × 10^‐4 M and from 1.3 × 10^‐3 M to 1.2 × 10^‐2 M with an excellent detection limit of 1.9 × 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.