Enhanced luminol–O2 chemiluminescence reaction by CuO nanoparticles as oxidase mimics and its application for determination of ceftazidime

Abstract

A cursory survey of the literature shows that although peroxidase-like activity is a well-known and well-applied property of CuO nanoparticles (CuO NPs), the oxidase-like activity of CuO NPs is a property that is somehow neglected to be incorporated in analytical applications. The present work reports that CuO NPs, with intrinsic oxidase-like activity, catalyze the oxidation of luminol by dissolved oxygen (DO) to generate enhanced chemiluminescence (CL) emission. In addition, it was found that ceftazidime (CFZM) has an effective attenuating effect on the CuO NP-catalyzed luminol–O₂ CL system in alkaline medium. Based on these findings, a simple and sensitive CL method for the determination of CFZM was developed. The linear dynamic range of the method was 1 × 10⁻⁷ to 4 × 10⁻⁶ mol L⁻¹ with a correlation coefficient of the calibration line being r² = 0.9902. The limit of detection (LOD) was equal to 2.5 × 10⁻⁸ mol L⁻¹ and the relative standard deviation of the method with respect to 2.5 × 10⁻⁷ mol L⁻¹ CFZM was equal to 4.5% (n = 4). The applicability of the method was demonstrated for pharmaceutical preparations, and tap and ground waters. The CuO NPs were synthesized by a quick-precipitation method and their particle size distribution was analyzed. The synthesized CuO NPs were characterized by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Dynamic light scattering (DLS) was also used for analyzing the particle size-distribution of CuO NPs. In addition, the possible mechanism for the CL reaction is discussed.