Co3O4 nanoparticles-enhanced luminol chemiluminescence and its application in H2O2 and glucose detection

In this study, Co3O4 nanoparticles were synthesized by a hydrothermal method and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The as-prepared Co3O4 nanoparticles were used to amplify a weak chemiluminescence (CL) of a luminol-H2O2 system. The results of UV-visible absorption and CL spectra showed that the CL luminophor was 3-aminophthalate, indicating that the CL enhancement of the luminol-H2O2 system was attributed to the intrinsic catalytic effect of Co3O4 nanoparticles acting as the electron transfer accelerators and radical generation proliferators. Based on the H2O2 concentration dependence of the catalytic activity of Co3O4 nanoparticles, a simple, sensitive and relatively selective CL assay for H2O2 was constructed. Under the optimized conditions, a linear relationship was obtained between the CL intensity and H2O2 concentration in the range of 1.0 × 10−8–1.0 × 10−5 mol L−1 with a detection limit of 1.1 × 10−9 mol L−1. When combined with the glucose oxidase-catalyzed oxidation reaction, the sensitive detection of glucose could be realized. The linear range for glucose was from 1.0 × 10−7 to 1.0 × 10−5 mol L−1 with a detection limit of 8.0 × 10−8 mol L−1. This proposed method has been successfully applied to the determination of H2O2 in rain water and glucose in serum samples.