In this study, a novel SiC/rGO nanocomposite-modified glassy carbon electrode (SiC/rGO/GCE) was developed as a simple, cost-effective, and efficient electrochemical platform for metronidazole (MTZ) detection. The combination of silicon carbide (SiC) and reduced graphene oxide (rGO) provides a favorable interface with a high electroactive surface area, efficient electron transfer, and enhanced electrocatalytic activity. The mor-phology and surface characteristics of the modified electrode were investigated by scan-ning electron microscopy (SEM), while its electrochemical properties were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The results confirmed successful electrode modification and improved electron-transfer kinetics compared with the bare GCE. The main experimental parameters were systematically optimized, with the optimum conditions established at pH 10, an accumulation time of 300 s, and an accu-mulation potential of 0.5 V. Under these conditions, the SiC/rGO/GCE exhibited a broad linear response to MTZ over the concentration range of 5–5000 µmol/dm³, with a detection limit of 0.5 µmol/dm³ (S/N ≥ 3). The enhanced analytical performance is attributed to the synergistic contribution of rGO and SiC, where rGO promotes rapid electron transport and provides a large electroactive surface, while SiC contributes additional active sites and structural stability. The sensor was successfully applied to pharmaceutical samples, providing recoveries of 99.85–102.29% with RSD values below 2%. These results demon-strate the practical potential of the proposed sensor for reliable MTZ determination. Fur-ther validation in food and biological matrices and comparison with reference chromato-graphic methods will be necessary to establish its broader analytical applicability.

Most of the pollutants from the atmosphere of the urbanised area get into the soil. Due to the increase in population and motor transport in Almaty city there is a high level of atmospheric air pollution, increased content of heavy metals in the soil. Accumulation of heavy metals by green trees from the soil positively affects soil conditions, in this regard, it is relevant to assess the current state of soil cover of regions where Thuja occidentalis L. and Platycladus orientalis L. trees grow. In the article, to determine the influence of western and eastern thuja trees on soil composition, soil were obtained with coordinates at point 2 and control point, where trees of thuja species grew side by side. Total and mobile content of heavy metals in soil (Cu, Zn, Mn, Fe) were determined by atomic absorption spectrometry. Morphological characterisation of the soil cover was made, granulometric composition and soil types were determined by the Tyurin method. Point 1 Thuja occidentalis L. humus content in soil cuttings on which the tree was growing showed maximum content of 3.82% in 0-10 cm, while Platycladus orientalis L. when growing the humus content is low 1.86%, the soil in point 2 opposite Platycladus orientalis L. humus content of 2.96% when growing Thuja occidentalis L. (2.14%) has a higher humus content compared to the augmented soil. Thuja occidentalis L. and Platycladus orientalis L. in the control, where the species grew together, the humus content is 3.1%. the pH value ranged from 8.26 to 8.81, with soil cuttings generally showing a strong alkaline environment. Among the heavy metals, Zn, Cu and Fe were found to be significantly above the MAC in the soil, meaning that the soils of the study area were contaminated with heavy metals. At profile 1, the soil on which western thuja grew has less amount of Zn, Cu, Mn, Fe compared to the soil on which eastern thuja grew, Mn- and others are above MAC. At profile 3, only the Fe size of Platycladus orientalis L. is higher in the overgrown soil. Thuja occidentalis L. and Platycladus orientalis L. where the species grew together, the amount of Mn decreased by 452.2µg/kg. The study showed that the accumulation of heavy metals in the soil decreased when growing the western thuja species compared to the eastern thuja species. Keywords: Thuja, soil cover, granulometric composition, humus, heavy metals, MPC