The effective peroxidase-like activity of chitosan-functionalized CoFe2O4 nanoparticles for chemiluminescence sensing of hydrogen peroxide and glucose

Abstract

Here, we report a highly simple and general protocol for functionalization of the CoFe₂O₄ NPs with chitosan polymers in order to make CoFe₂O₄ NPs disperse and stable in solution. The functionalized CoFe₂O₄ NPs (denoted as CF-CoFe₂O₄ NPs) were characterized by scanning electron microscope (SEM), thermogravimetric (TG), X-ray diffraction (XRD) and FT-IR spectra. It was found that the CoFe₂O₄ NPs were successfully decorated and uniformly dispersed on the surface of chitosan without agglomeration. The CF-CoFe₂O₄ NPs were found to increase greatly the radiation emitted during the CL oxidation of luminol by hydrogen peroxide. Results of ESR spin-trapping experiments demonstrated that the CF-CoFe₂O₄ NPs showed catalytic ability to H₂O₂ decomposition into ˙OH radicals. On this basis, a highly sensitive and rapid chemiluminescent method was developed for hydrogen peroxide in water samples and glucose in blood samples. Under optimum conditions, the proposed method allowed the detection of H₂O₂ in the range of 1.0 × 10⁻⁹ to 4.0 × 10⁻⁶ M and glucose in the range of 5.0 × 10⁻⁸ to 1.0 × 10⁻⁵ M with detectable H₂O₂ as low as 500 pM and glucose as low as 10 nM, respectively. This proposed method has been successfully applied to detect H₂O₂ in environmental water samples and glucose in serum samples with good accuracy and precision.