Ученые создали новый сенсор для быстрого обнаружения алюминия в почве и продуктах питания

The sensor achieves a rapid response time of five seconds, enabling sensitive detection of aluminum ions in complex matrices, including agricultural soil and commercial food products. These findings were published in Scientific Reports. Aluminum is abundant in the Earth’s crust and becomes more soluble and bioavailable when soil pH falls below 5.0. While widely used in various processes, its accumulation in biological systems can pose significant ecological and health risks. Long-term exposure to high aluminum levels has been investigated for possible effects on the nervous system, including Alzheimer’s and Parkinson’s diseases, as well as respiratory and renal complications. Conventional quantification methods, such as inductively coupled plasma mass spectrometry (ICP-MS), require complex instrumentation, high operational costs, and extensive sample preparation. These limitations have driven the development of ion-selective electrochemical sensors, which offer simpler, more cost-effective methods for detecting trace metals. Recent advancements in chemically modified CPEs have further enhanced their suitability for sensitive aluminum detection in other real-world applications. Fabrication of the Ion-Selective Electrode To address the limitations of conventional analytical methods, researchers employed an Al-FLU complex as the ionophore in a CPE. The electrode design converts the presence of aluminum ions into a measurable electrical response while maintaining stability during operation. Download a free copy of this page here! For fabrication, the Al-FLU complex was homogenized with high-purity graphite powder. Three plasticizers, tricresyl phosphate (TCP), dibutyl phthalate (DBP), and o-nitrophenyl octyl ether (o-NPOE), were evaluated for their effects on the paste’s mechanical stability, service life, and electrochemical performance. These plasticizers acted as solvent mediators, influencing the paste properties and allowing for uniform ionophore distribution across the sensing surface. Density functional theory (DFT) calculations were employed to examine the molecular properties of the sensing material. Using GaussView with the LANL2DZ (Los Alamos National Laboratory 2 Double Zeta) basis set, the molecular geometries of free flubendazole and the corresponding aluminum complex were optimized. The study compared their highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies to assess changes in electronic properties associated with aluminum complexation. Performance Metrics of the Developed Sensor Empirical testing indicated that the TCP-based formulation provided the strongest analytical performance. The optimized sensor contained 2.67% Al (III)-FLU, 30.54% TCP, and 66.79% graphite powder by weight, exhibiting a Nernstian slope of 20.0 ±0.683 mV per decade. The sensor demonstrated a linear response over a concentration range from 1.0 × 10-7 to 1.0 × 10-1 mol L-1, with a detection limit of 1.0 × 10-7 mol L-1. The equilibrium potential stabilized rapidly, indicating efficient ion exchange kinetics at the electrode/solution interface. The sensor maintained a stable response across a pH range of 3.4 to 5.5 and exhibited thermal stability from 10 °C to 60 °C, with an isothermal coefficient of 1.778 × 10-3 V/°C. DFT calculations revealed that the HOMO–LUMO energy gap decreased from 4.339 eV for free flubendazole to 1.442 eV for the aluminum complex, while the calculated dipole moment increased from 6.886 to 29.911 debye. These changes indicate substantial redistribution of electronic properties following aluminum coordination, supporting the interaction between the Al-FLU complex and aluminum ions that contributes to the sensor’s selectivity against interfering cations. Real-World Applications of the Sensor The practical viability of the novel ion-selective electrode was evaluated using prepared soil and food samples to assess its performance outside controlled laboratory conditions. Agricultural soil samples, including sandy soils, were analyzed for trace aluminum concentrations relevant to potential phytotoxic effects on root growth and crop yield. The sensor was also applied to commercial food products for aluminum determination. Its potentiometric measurements were validated against standard ICP spectrometry, with close agreement between the two methods supporting the accuracy of the sensor and its suitability for aluminum analysis in environmental and food samples. Conclusion Integrating the Al-FLU complex into a carbon paste matrix yielded a stable potentiometric sensor for aluminum-ion detection. The sensor provided a rapid response, a broad linear range, and a detection limit of 1.0 × 10-7 mol L-1, while maintaining its response across the tested pH and temperature ranges. Validation with agricultural soil and commercial food samples showed close agreement with ICP spectrometry, showing how, with development, the sensor could be used for aluminum monitoring in environmental and food samples. Furthermore, its relatively simple electrode composition and short response time suggest potential for field-based applications. Further work should focus on scalable fabrication, long-term stability, and evaluation across a wider range of environmental and food matrices. Journal Reference Fawzy, K.H., Zayed, M.A., Frag, E.Y. (2026). Characterization and performance of aluminum (III)-complex as an active material for potentiometric sensor. Scientific Reports. 16. DOI: 10.1038/s41598-026-66624-9. https://www.nature.com/articles/s41598-026-66624-9. 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