An electrochemical sensor using nickel-based metal-organic framework towards highly-sensitive detection of multiple heavy metal ions

Traditional methods for detecting heavy metals are often limited by specialized operator skills, extended analysis durations, and expensive equipment. This study aims to develop a portable electrochemical sensor for the simultaneous quantification of Pb²⁺ and Cu²⁺ in aqueous environments. The Polyamide-amine dendrimers/Nickel Metal-Organic Frameworks (PAMAM/Ni-MOFs) nanocomposite was synthesized and utilized as a sensing platform by modifying a glassy carbon electrode. The developed electrochemical sensor enables simultaneous detection through SWASV, demonstrating a linear response within the range of 1–100 μg/L and achieving ultralow detection limits (Pb²⁺: 1.21 μg/L; Cu²⁺: 0.77 μg/L), which are below the World Health Organization's recommended thresholds for drinking water (10 μg/L Pb²⁺; 2000 μg/L Cu²⁺). The platform exhibits remarkable specificity (ΔI < 17 % against tenfold interferents), repeatability (five electrodes, RSD < 3.56 %), and operational stability (over 95 % signal retention for 30 days), thereby meeting stringent criteria for on-site water quality assessment. This study presents a field-deployable electrochemical sensor based on PAMAM/Ni-MOFs nanocomposites, capable of concurrent detection of Pb²⁺ and Cu²⁺ within seven minutes. This system addresses the limitations of conventional methods through its compact design, cost-effectiveness, and ease of operation, positioning it as a significant advancement for environmental monitoring and industrial wastewater management.