Development of metal organic frameworks-agnp based electrochemical sensor for selective determination of PB+2 ions

The rapid and reliable detection of biomolecules and heavy metal ions at low concentrations is of great importance in the fields of health and environment. Electrochemical techniques provide low-cost, portable, and fast analysis opportunities in these areas. In order to enhance sensor performance, electrochemical sensors have been developed using metal organic frameworks with high surface area and tunable structure, multi walled carbon nanotubes with conductivity and durability, and metal nanoparticles with functional properties. In this study, UiO-66-NH₂, a type of hybrid metal organic frameworks offering superior features, was synthesized. By incorporating silver nanoparticles into this structure, a UiO-66-NH₂/AgNP composite was obtained. Carbon nanotubes and composite structures were employed for the modification of the glassy carbon electrode surface. To develop the sensor, cyclic voltammetry was applied using these modified electrodes, and tests were conducted on analytes such as certain biomolecules and heavy metals. The synthesized materials were characterized and confirmed through techniques including absorption spectroscopy, FTIR, DSC, SEM-EDX, and XRD. In the detection of analytes, results obtained from the developed electrochemical sensor system were evaluated. Characterization results confirmed the positive effect of incorporating silver nanoparticles into the metal organic frameworks structure. In electrochemical measurements, the current response increased with the use of multi walled carbon nanotubes, and this enhancement became more pronounced with the addition of UiO-66-NH₂/AgNP. The developed GCE/MWCNT/MOF-AgNP hybrid electrode system shows potential as an electrochemical sensor with sensitivity and selectivity for Pb²⁺ detection. The LOD was calculated as ≈ 3.199 µM and the LOQ as ≈ 10.664 µM.