Fluorometric method for the determination of hydrogen peroxide and glucose with Fe3O4 as catalyst

In this paper, we utilized the instinct peroxidase-like property of Fe3O4 magnetic nanoparticles (MNPs) to establish a new fluorometric method for determination of hydrogen peroxide and glucose. In the presence of Fe3O4 MNPs as peroxidase mimetic catalyst, H2O2 was decomposed into radical that could quench the fluorescence of CdTe QDs more efficiently and rapidly. Then the oxidization of glucose by glucose oxidase was coupled with the fluorescence quenching of CdTe QDs by H2O2 producer with Fe3O4 MNPs catalyst, which can be used to detect glucose. Under the optimal reaction conditions, a linear correlation was established between fluorescence intensity ratio I0/I and concentration of H2O2 from 1.8 × 10−7 to 9 × 10−4 mol/L with a detection limit of 1.8 × 10−8 mol/L. And a linear correlation was established between fluorescence intensity ratio I0/I and concentration of glucose from 1.6 × 10−6 to 1.6 × 10−4 mol/L with a detection limit of 1.0 × 10−6 mol/L. The proposed method was applied to the determination of glucose in human serum samples with satisfactory results.