Synthesis of ZnO nanoparticles on carbon graphite and its application as a highly efficient electrochemical nano-sensor for the detection of amoxicillin:analytical application: milk, human urine, and tap water

Amoxicillin is an antimicrobial of the penicillin class discovered in 1928. The objective of this paper is to construct a simple platform for electrocatalytic detection of amoxicillin using a ZnO@CPE nano-sensor constructed using simple and inexpensive processes using hydrothermal methods. Our results show that the constructed ZnO@CPE electrode exhibits excellent electrocatalytic activity compared to the unmodified electrode, with consistent, reproducible, and stable behavior. The electrochemical behavior of the amoxicillin oxidation reaction is diffusion controlled and fully reversible. The effect of the pH of the phosphate buffer solution on the antibacterial behavior of amoxicillin shows that the number of protons and electrons were equal. The morphology and chemical composition of the constructed nanoparticles were characterized by scanning electron microscope, transmission electron microscope, high-resolution transmission electron microscope, X-ray diffractometer, and infrared spectroscopy. Suggest the formation of zinc oxide nanocrystals on the carbon sheets with an order size of 22.957 nm. The diffusion coefficient and catalytic rate constant were 1.135 × 10–4 cm2/s and 8.314 × 103 mol.l−1/s, respectively. The proposed nano-sensor demonstrated a wide linearity range from 10–4 M to 10–6 M with LOD = 1.21 × 10–7 M and LOQ = 3.32 × 10–7 M according to the square-wave voltammetry method. The ZnO@CPE nano-sensor was examined for the detection of amoxicillin in real samples. Schematic concept of amoxicillin detection on the electrocatalytic surface of the nano-sensor fabricated with ZnO@CPE.