Highly sensitive [Ru(bpy)3]\u3csup\u3e2 +\u3c/sup\u3e/Nafion® modified indium tin oxide-based sensor for heavy metal detection

Indium tin oxide-coated glass substrates were modified with tris (2,2′-bipyridyl) ruthenium (II) dichloride hexahydrate [Ru(bpy)3]2 +/Nafion® solution via dip-coating. The Nafion®—[Ru(bpy)3]2 + ratio was varied to optimize the sensitivity of the modified electrodes in detecting lead (Pb2 +) and cadmium (Cd2 +). The surface morphology of the deposited thin film was characterized by scanning electron microscopy (SEM). The lowest concentration detected was 0.007 μM (0.001 μg/mL) and 4.91 μM (0.552 μg/mL) for lead and cadmium, respectively. The optimum Nafion® volume concentration in the film was 0.4% which gave an average film thickness of 217.90 nm. © 201