Green nanomaterial-based electrochemical sensors for the rapid detection and determination of barium in biological and wastewater samples

A highly sensitive electrochemical sensor based on copper-iron layered double hydroxides (Cu-Fe LDH) has been developed for the detection of barium ions (Ba²⁺), addressing the urgent need for reliable monitoring of this toxic element in environmental and biological samples. The Cu-Fe LDH nanomaterial was synthesised and characterised using various techniques, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), surface area analysis, for confirming its uniform morphology and significant surface area, which are critical for enhanced electrochemical performance. The electrochemical behaviour of the sensor was systematically investigated using cyclic voltammetry (CV). Key parameters such as electrode composition, electrolyte type, pH, scan rate, and selectivity were optimised to establish the most favourable conditions for barium detection. The calibration curve exhibited a linear response over a wide concentration range of 0.1 μM to 220 mm, with a limit of detection (LOD) of 63.7 nM and a limit of quantification (LOQ) of 193.3 nM, demonstrating the sensor’s high sensitivity. Furthermore, the Cu-Fe LDH-based electrode showed remarkable selectivity towards barium ions in the presence of common interfering ions, including cadmium, magnesium, copper, cobalt, nickel, zinc and calcium. The reproducibility, stability and repeatability of the sensor were confirmed through extensive testing, underscoring its potential for real-world applications and in water treatment field. This study not only highlights the effectiveness of Cu-Fe LDH in improving the sensitivity and selectivity of electrochemical sensors but also provides a promising approach for the detection of hazardous materials in environmental monitoring, thereby contributing to public health safety. Most importantly, the proposed method demonstrated exceptional eco-friendliness by lowering toxicity, waste, energy, and reagent loads.