Synthesis and characterization of polymeric films and nanotubule nets used to assemble selective sensors for nitrite detection in drinking water

Platinum electrodes were modified by electropolymerized films and polymer nanotubule nets and were applied to nitrite detection in drinking water. Several analytical parameters were investigated such as: different monomers (1,2-, 1,3-, 1,4-DAB, pyrrole, o-anisidine, 1,8-DAN), permeability toward nitrites and other interferences, permselectivty toward nitrites, operational and long-term stability. The best performances were obtained with a poly(1,3-DAB) film and the assembled sensor was characterized morphologically by scanning electron microscope and electrochemically by cyclic voltammetry and amperometry coupled to flow injection analysis (FIA), in terms of linear range of concentration (10–1000 μM), limit of detection (2 μM), reproducibility (R.S.D.%: 0.4) and linear regression (y (μA) = 1.14x (μM) + 2.6). Finally real samples (tap and mineral drinking water) were analyzed by adding standard nitrite solutions and the recovery was evaluated showing no matrix effect on sensor performances.