Highly ordered platinum-nanotube arrays for oxidative determination of trace arsenic(III)

A novel method for the oxidative determination of trace arsenic(III) was investigated on highly ordered platinum-nanotube array electrodes (PtNTAEs). The PtNTAEs with a highly organized structure were fabricated by electrochemical deposition of platinum in a 3-aminopropyltrimethoxysilane-modified porous anodic alumina template (PAA). The morphologies and structures of PtNTAEs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical experiments proved that the PtNTAEs exhibited better performance for As(III) analysis in comparison with platinum nanoparticles-coated GCE (Pt_nano/GCE) or Pt foil electrode. The PtNTAEs showed to provide higher reproducibility and lower detection limit. The relative standard deviation (RSD) was 3.5% for 50 repeated measurements of 20 μM As(III), and the limit of detection (LOD) was 0.1 ppb, which was typically 1–2 orders of magnitude lower than that of Pt_nano/GCE or Pt foil electrode.