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Gold nanoparticles/carbon nanotubes (Au-NPs/CNTs) composites were rapidly synthesized by microwave radiation, and firstly applied for the determination of trace mercury(II) by anodic stripping voltammetry (ASV). The structure and composition of the synthesized Au-NPs/CNTs nanocomposites were characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), UV–vis absorption spectroscopy and cyclic voltammetry. Au-NPs/CNTs nanocomposites modified glassy carbon electrode (Au-NPs/CNTs/GCE) exhibited excellent performance for Hg(II) analysis. A wide linear range (5 × 10−10–1.25 × 10−6 mol/L) and good repeatability (relative standard deviation of 1.84%) were obtained for Hg(II) detection. The limit of detection was found to be 3 × 10−10 mol/L (0.06 μg/L) at 2 min accumulation, while the World Health Organization’s guideline value of mercury for drinking water is 1 μg/L, suggesting the proposed method may have practical utility. Keywords: Microwave-irradiated synthesis, Gold nanoparticles, Carbon nanotubes, Voltammetry, Mercury

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 (Ptnano/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 Ptnano/GCE or Pt foil electrode. Keywords: Highly ordered platinum-nanotube array, Arsenic, Voltammetry, Porous anodic alumina template, Heavy metals

Platinum nanoparticles/carbon nanotubes (Ptnano/CNTs) were rapidly synthesized by microwave radiation, and applied for the oxidative determination of arsenic(III). The transmission electron microscopy (TEM) revealed the size of synthesized Pt nanoparticles with nominal diameter of 15 ± 3 nm. Ptnano/CNTs modified glassy carbon electrode (Ptnano/CNTs/GCE) exhibited better performance for arsenic(III) analysis than that of Pt nanoparticles modified GCE (Ptnano/GCE) by electrochemical deposition or Pt foil electrode. Excellent reproducibility of the Ptnano/CNTs/GCE was obtained with the relative standard deviation (RSD) of 3.5% at 20 repeated analysis of 40 μM As(III), while the RSD was 9.8% for Ptnano/GCE under the same conditions. The limit of determination (LOD) of the Ptnano/CNTs/GCE was 0.12 ppb, which was 1–2 orders of magnitude lower than that of Ptnano/GCE or Pt foil electrode. Keywords: Microwave-irradiated synthesis, Platinum nanoparticles, Voltammetry, Carbon nanotubes, Arsenic