A new electrochemical sensor detects trace aluminium in soil and food, offering rapid, sensitive measurements for environmental monitoring and routine analysis across diverse sample types.
Researchers have developed an electrochemical aluminium sensor that can detect trace levels of the metal in soil and food samples, offering a simpler approach to environmental and food monitoring. The sensor uses an aluminium(III)-flubendazole (Al-FLU) complex incorporated into a chemically modified carbon paste electrode.
Aluminium is widely present in environmental and food samples, but elevated concentrations can raise health and agricultural concerns. Conventional techniques such as inductively coupled plasma spectrometry require costly instrumentation, skilled operation and extensive sample preparation. The new potentiometric sensor is designed to provide a more accessible alternative for aluminium-ion detection.
The sensing electrode combines Al-FLU with tricresyl phosphate (TCP) and graphite. Researchers evaluated different compositions before identifying an optimised formulation containing 2.67% Al-FLU, 30.54% TCP and 66.79% graphite by weight. The formulation provided the strongest analytical response while maintaining stable operation.
The sensor demonstrated a near-Nernstian response of about 20.0 mV per decade and a detection limit of 1.0 × 10⁻⁷ mol/L. It maintained a stable response across a pH range of 3.4 to 5.5 and showed thermal stability between 10°C and 50°C. Density functional theory calculations were also used to examine changes in molecular properties associated with aluminium complex formation.
Performance was assessed using agricultural soil samples, including saline soils, where aluminium concentrations can influence plant growth and crop yield. The sensor was also tested on commercial food products. Results from potentiometric measurements showed close agreement with conventional ICP spectrometry, supporting its accuracy.
The relatively simple electrode composition and rapid response could make the technology useful for field-based aluminium screening. Its potential applications include environmental monitoring, agricultural assessment and food analysis.
Further development will focus on improving long-term stability, scaling fabrication and evaluating performance across a wider range of environmental and food samples.
