Diamond electrodes for trace alpha pollutant sequestration via covalent grafting of nitrilotriacetic acid (NTA) ligand

Graphical abstract: - Highlights: • A straightforward method for NTA ligand covalent immobilization on BBD electrode was described. • This work also demonstrated for the first time that the BDD electrode could easily be functionalized using electrochemical oxidation of aromatic aminated compounds. • NTA functionalized surfaces exhibit a reversible actinide trace sequestration. - Abstract: We describe a very simple and efficient route to functionalize boron-doped-diamond (BDD) electrodes with a chelating nitrilotriacetic acid (NTA) ligand. The BDD electrode surface was first functionalized with a carboxylic acid group via electrochemical grafting of 4-aminophenylcarboxylic acid in aqueous solution and subsequently linked to NTA ligand via a coupling reaction with amine terminated NTA ligand in PBS solution (pH 7.5). Modified BBD surfaces were characterized using X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The present study has demonstrated that NTA functionalized BDD surfaces can successfully be used for reversible ²⁴¹Am sequestration in aqueous solution