Fabrication of Au nanowire array for anodic stripping voltammetry determination of trace Pb2+ ions

Well aligned Au nanowire (AN) array was synthesized by galvanostatic deposition within the anodic aluminum oxide (AAO) template. Morphologies of ANs were examined with scanning electron microscopy (SEM) indicating well-distributed ANs with a diameter of about 80 nm. Electrochemical behaviors of Au-disc electrode and ANs electrode in NaAc-HAc buffer solution in absence and presence of 30 mu g/L Pb2+ ions were compared by the use of cyclic voltammetry. Pb2+ ions were determined by anodic stripping voltammetry (ASV) method in a three-electrode system with ANs array as the working electrode. Optimizations were obtained on buffer solution, hole enlarging time of template, preconcentration potential, and preconcentration time for ASV determination of Pb ions. The optimized parameters were 0.1 M NaAc-HAc buffer solution with a pH value of 4.5, hole enlarging time of 5 min, preconcentration potential of -1.2 V and preconcentration time of 150 s. In this optimized condition, the ANs sensor achieved a sensitivity of 1.095 mu A/(mu g/L) within a linear range from 5 to 60 mu g/L. (C) 2012 Elsevier B.V. All rights reserved.