A Fe₃O₄‐Based Chemical Sensor for Cathodic Determination of Hydrogen Peroxide

Abstract

Abstract A new cathodic scheme for hydrogen peroxide (H 2 O 2 ) measurement by Fe 3 O 4 ‐based chemical sensor was described. The unique characteristic of electrocatalytic property was firstly investigated by voltammetry. And then the amperometric response of H 2 O 2 was measured at −0.2 V (vs. Ag/AgCl) by Fe 3 O 4 modified glassy carbon rotating disk electrode. The kinetic parameter was also calculated from Koutecky‐Levich plot, and the value was 6.4×10 −4 cm s −1 in pH 3 citrate buffer. In order to benefit the possible biomedical applications, Fe 3 O 4 /chitosan modified electrode was also investigated in this experiment. There were several characteristic enhancements by the coated chitosan thin film for H 2 O 2 sensor. The calibration curves were found to be linear up to 4.0 and 5.0 mM ( r =0.999) in pH 3 and 7 with the detection limits of 7.6 and 7.4 μM L −1 ( S/N =3). The stability was evaluated by the results of half‐life time ( t 50% ) for 9 months at room temperature and 24 months at 4 °C.