Polycyclic aromatic hydrocarbon detection by electrochemiluminescence generating Ag/TiO(2) nanotubes.

Highly ordered TiO(2) nanotube arrays are with unique photoelectrical properties due to their highly ordered nanostructure and the resulted short charge transportation path. We report, for the first time, on the application of Ag nanoparticle-modified TiO(2) nanotubes (Ag/TiO(2) NTs) in the electrochemiluminescence detection of polycyclic aromatic hydrocarbons (PAHs) using the Ag/TiO(2) NT film as working electrode and S(2)O(8)(2-) as coreactant, with benzo(a)pyrene (BaP) as the model compound. The hydrophobic BaP absorbs onto the TiO(2) NTs surface, and oxidized with consumption of the excited TiO(2) (TiO(2)(*+)) resulting in a decrease in ECL. Under the optimal conditions, a detection limit of 1.0 x 10(-12) M is achieved with a linear range of 3.0 x 10(-12) approximately 1.0 x 10(-9) M. Compounds which can not be oxidized by the excited TiO(2) (TiO(2)(*+)), such as benzene, naphthalene (NAP), anthracene (ANT), and tris-2,3-dibrominepropyl isocyanurate (TBC) show little interference on the detection, whereas PAHs with more than four rings can be detected by the proposed method.