A solid-state pH sensor based on WO3-modified vertically aligned multiwalled carbon nanotubes

In this communication, a novel solid-state pH sensor based on WO3/MWNTs nanocomposite electrode will be reported. WO3 nanoparticles were homogeneously coated on vertically aligned MWNTs by magnetron sputtering. Potentiometric pH response of the WO3/MWNTs electrode in Britton–Robinson buffers revealed a linear working range from pH 2 to12 with a slope of about −41 mV pH−1 and a response time less than 90 s. The stability of the electrode remained over a month. Moreover, the WO3/MWNTs electrode displayed excellent anti-interference property. Compared to conventional pH sensors, the pH sensor based on WO3/MWNTs nanocomposite electrode also showed excellent reproducibility, high stability and superb selectivity.