A photoelectrochemical sensor for lead ion through electrodeposition of PbS nanoparticles onto TiO2 nanotubes

A selective and sensitive photoelectrochemical sensor for lead ion (Pb 2+ ), which is based on the generated photocurrents of lead sulfide (PbS) nanoparticles under visible light irradiation , has been developed with theoretical and technical simplicity. The PbS nanoparticles are in-situ electrodeposited onto TiO 2 nanotube arrays with the gradual addition of Pb 2+ . The present sensor shows high selectivity against other metal ions , broad linear range from 10 −8   M to 10 −5   M, and low detection limit of 0.39   nM (∼0.08   ppb), which is much lower than the standard of Pb 2+ in drinking water formulated by World Health Organization (WHO). Thus, the strategy has been applied to successful detection of Pb 2+ in tap and lake water samples. The results for determination of Pb 2+ in lake water samples obtained by the present method and atomic adsorption spectroscopy (AAS) are consistent. However, the detection of Pb 2+ in tap water samples has just been realized by the present method, but AAS cannot, because of its low detection limit.