Ferrocene Branched Chitosan for the Construction of a Reagentless Amperometric Hydrogen Peroxide Biosensor

Chitosan was chemically branched with ferrocene moieties and further used as a support for the immobilization of horseradish peroxidase on a glassy carbon electrode. The reagentless biosensor device showed a linear amperometric response toward hydrogen peroxide concentrations between 35 × 10 −6 M and 2.0 × 10 −3 M . The biosensor reached 95% of the steady‐state current in about 20 s and its sensitivity was 28.4 × 10 −3 µA ·  M −1 . The enzyme electrode retained 94% of its initial activity after 2 weeks of storage at 4 °C in 50 × 10 −3 M sodium phosphate buffer at pH 7.0.