Lead ion (Pb 2+ ) electrochemical sensors based on novel Schiff base ligands

• Published in: Environmental science water research & technology 2024-10, Vol.10 (11), p.2997-3006
• Main Authors: Akbari, Zahra, Abid, Khouloud, Iannazzo, Daniela, Montazerozohori, Morteza, Fazio, Enza, Neri, Fortunato, Corsaro, Carmelo, Neri, Giovanni
• Format: Article
• Language: English
• Subjects: Butane; Chemical analysis; Chemical sensors; Chemical synthesis; Diamines; Electrochemistry; Electron microscopy; Ethane; Fourier analysis; Fourier transforms; Gold; Heavy metals; Imines; Infrared analysis; Infrared spectroscopy; Lead; Ligands; Metal ions; Nanoparticles; Nitrogen; NMR; Nuclear magnetic resonance; Reflectance; Scanning electron microscopy; Seawater; Sensors; Spectrum analysis; Thermodynamic properties; Ultraviolet spectroscopy; Water analysis
• ISSN: 2053-1400; 2053-1419
• DOI: 10.1039/D4EW00485J

In this study, a novel bidentate Schiff base ligand, namely (1 E ,1′ E ,2 E ,2′ E )- N , N ′-(butane-1,4-diyl)bis(3-(2-methoxyphenyl)prop-2-en-1-imine) (L 1 ), and a tetradentate Schiff base ligand, namely N 1, N 2-bis(2-(((1 E ,2 E )-3-(4-(dimethylamino)phenyl)allylidene)amino)ethyl)ethane-1,2-diamine (L 2 ), were successfully synthesized through a simple procedure. The synthesized Schiff base ligands were characterized by scanning electron microscopy (SEM) analysis, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectroscopy. Moreover, the thermal behavior was studied through thermogravimetric (TG)/differential thermogravimetric (DTG)/differential thermal (DT) analyses under a nitrogen atmosphere. Subsequently, the features and performances of the synthesized ligands (L 1 and L 2 ) as electrochemical sensors for the detection of heavy metal ions (HMIs) have been investigated. A different behavior was noticed using these two ligands, with L 1 being the best candidate for developing a modified screen-printed carbon electrode (L 1 /SPCE) electrochemical Pb 2+ sensor. To improve further the performances, gold nanoparticles (AuNPs) were deposited by an electrochemical process on the L 1 /SPCE platform. The developed AuNPs-L 1 /SPCE sensor displayed enhanced lead ion sensing with a high sensitivity of 56.78 μA μM −1 cm −2 and a detection limit of 0.298 μM. This novel sensor demonstrated promising performances for the detection of Pb 2+ ions in real seawater with no sample treatment.