Enhanced luminol chemiluminescence by Co–Fe LDH nanoplates and its application in H2O2 and glucose detection

Abstract

It was found that Co–Fe layered double hydroxides (Co–Fe LDHs), other than intercalated LDHs, could catalyze the luminol–H₂O₂ chemiluminescence (CL) reaction and generate a strong CL signal. The as-prepared Co–Fe LDHs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on the CL spectra, UV-visible absorption spectra and free radical scavenging assay, a possible CL mechanism was proposed. Under optimum conditions, a good linear relationship between the CL intensity and H₂O₂ concentration in the range of 1.0 × 10⁻⁸ to 3.0 × 10⁻⁶ mol L⁻¹, with the limit of detection of 5.0 × 10⁻⁹ mol L⁻¹, was obtained. Based on the glucose conversion into H₂O₂ by glucose oxidase, the sensitive detection of glucose could be realized with the limit of detection of 2.0 × 10⁻⁸ mol L⁻¹. This proposed method has been applied to the determination of H₂O₂ and glucose in real samples with satisfactory results.