Gold Copper-1,3,5-Benzene Dicarboxylate (Cu-BTC) Nanocomposite as an Electrochemical Sensor for Antimony Speciation by Square Wave Anodic Stripping Voltammetry (SWASV)

We combined Au nanoparticles with Copper-1,3,5-benzene dicarboxylate (Cu-BTC) to modify the glassy carbon electrode (GCE) for Sb determination in water by square wave anodic stripping voltammetry (SWASV). Sb(V) is reduced to Sb(III) by potassium iodide (KI) and ascorbic acid (AA), allowing Sb(V) determination by subtracting Sb(III) from total Sb. The sensor's selectivity and stability stem from Sb-Cu2+ interaction, Cu-BTC's 3D structure, electrocatalytic activity and conductivity of gold nanoparticles (AuNPs). The sensitivity and detection limit of Sb(III) were 0.38 μA/μg/L and 0.24 μg/L. The sensitivity and detection limit of Sb(V) were 0.32 μA/μg/L and 0.38 μg/L. The Au/Cu-BTC sensor showed good reproducibility and recoveries in natural waters, showing promise for the practical determination of Sb(III/V) species.