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

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)-O-center dot 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 x 10(-9) to 4.0 x 10(-6) M and glucose in the range of 5.0 x 10(-8) to 1.0 x 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.