Green Synthesis of Copper Oxide Nanoparticle Decorated Polypyrrole-Chitosan on Pencil Graphite Electrode for Enzyme-Free Glucose Sensors

Abstract

Here we report that we use Vitis vinifera as a reducing and stabilizing agent during the green synthesis of CuO nanoparticles (NPs). Compared to chemical and physical synthesis methods, this approach is non-toxic, environmentally friendly, and inexpensive. Scanning electron microscopy (SEM-EDS), X-ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FT-IR) and UV–visible spectroscopy were used to investigate the characteristics of the gained particles. It showed that NPs synthesized with Vitis vinifera extract had high purity and an average particle size average of 60 nm. Then, the sensor activity of materials obtained at different concentrations of copper oxide nanoparticles decorated polypyrrole-chitosan on pencil graphite electrode was investigated. PPy-Chi(2.5 mg)/PGE containing 2.5 mg CuO NP electrode exhibited a linear range at concentrations of 0.2–10.0 mM and a detection limit as low as 0.740 μM. The incorporation of CuO NPs has greatly increased the sensor activity of the surface electrode, which serves as a highly active site. In addition, the stability achieved along with excellent sensing ability in beverages means that the electrodes are suitable for practical applications.