Fabrication of Environmental Monitoring Amperometric Biosensor Based on Alkaloids Compound Derived from Catharanthus Roseus Extract Nanoparticles for Detection of Cadmium Pollution of Water

In this work, the Soxhlet extraction method extracted the Catharanthus roseus plant to obtain alkaloids, and then converted them into Chitosan nanoparticles (CSNPs)-linker-alkaloids compound. The CSNPs- linker-alkaloids compound was characterized by X-ray diffractometer (XRD), which shows the sample has an orthorhombic structure with crystallite size in nano-dimension; in Fourier Transform Infrared spectroscopy (FTIR), a new distinct band appears at ۱۷۰۸.۹۳ cm-۱ which is attributed to C=O esterification, which indicates the success of the reaction. Scanning electron microscope (SEM) images show that the final product has two shapes, spherical particles and tubes in nano-dimensions, and is close to each other compared to normal Chitosan. The cyclic voltammetric technique was used to study the electrochemical analysis of the newly modified electrode with extract plant and CSNPs-linker-alkaloids compound on the glassy carbon electrode. Citrate-Phosphate buffer, KCl electrolytes at pH ۵, ۲۰ cycles, buffer volume to ۱۰۰۰ μl and ۰.۵ Vs-۱, the extract plant, CSNPs-linker-alkaloids storage for six months conditions are considered. The modified electrode was used to detect cadmium (Cd) ions in the range of (۰.۰۲ and ۰.۱۶) ppm. The best was sensitivity R² equal to ۰.۹۸ for oxidation and ۰.۹۷۵ for reduction. The modified electrodes; (GCE/extract plant( and )GCE/CSNPs-linker-alkaloids) act as suitable sensors for heavy metals detection in water.