Novel gold nanoparticles-Schiff base electrochemical sensor for the determination of lead (II) ions in biological samples

In this investigation, a novel tetradentate Schiff base ligand, (ligand L) was synthesized using a simple chemical route assisted by triethylenetetramine with 4-dimethylaminocinnamaldehyde in ethanol. The chemical structure of the as-synthesized ligand was characterized using nuclear magnetic resonance (NMR) and UV-visible spectroscopy. This ligand was then employed to modify the working electrode of screen-printed carbon electrode (SPCE) for developing a modified L/SPCE sensor finalized to detection of lead ions (Pb²⁺). The electrochemical characteristics of the sensor were assessed by Square Wave Anodic Stripping Voltammetry technique (SWASV). To further enhance the sensitivity, gold nanoparticles (AuNps) were deposited on the surface of the working electrode for obtaining an AuNps-L/SPCE sensor. This device shows a linear response to Pb²⁺ until to 0.6 µM, a sensitivity of 897 µA µM^-1 cm^-2 and a limit of detection (LOD) of 0.38 μM. This successful strategy offers promising avenues for lead ion detection also in urine.