Ecofriendly Synthesis of Tenorite (CuO) Nanoparticles Composite with β-cyclodextrin as an Electrochemical Sensor for the Determination of the Anticancer Drug Phloretin

Abstract

The present study reports the eco-friendly synthesis of single-phase tenorite (CuO) nanoparticles using an aqueous extract of Plectranthus scutellarioides for the first time. These CuO nanoparticles were combined with β-cyclodextrin (β-CD) to form CuO@β-CD nanocomposite. The prepared CuO@β-CD nanocomposite was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), fourier-transform infrared (FT-IR), zeta potential and the particle size analyser techniques. The nanocomposite was further utilized to fabricate an electrochemical sensor for the electrochemical investigation of an anticancer drug, phloretin (PHL). PHL exhibited two irreversible oxidation peaks at 0.807 V and 1.126 V on CuO@β-CD/GCE in phosphate buffer solution of pH 3. A 9-fold increment in the oxidation peak current of PHL was seen at CuO@β-CD/GCE when compared to that at bare/GCE. The oxidation peak current was observed to vary linearly with the concentration of PHL in the range of 0.05–102.04 μM for square wave voltammetric (SWV) method. The values of limit of detection (LOD) and limit of quantification (LOQ) were calculated and found to be 0.012 and 0.041 μM, respectively. The low relative standard deviation (RSD) values for inter- and intra-day assays revealed the good reproducibility and stability of the proposed method.