Polyanilines Modified Electrodes to be Assayed as Halides Sensors

摘要

One of the new uses for polyanilines (PANIs) is as sensors, being able to measure the concentration ofdifferent types of compounds. As a positive charge exists on PANI nitrogen, nucleophilic compoundscan interact with the polymer leading to an observable and measurable change. In this case,modification of Pt electrodes with polymers derived from the linear structure of PANI previouslyreported by us, namely (poly [2,6-di(thiophen-2-yl)aniline]; poly (2,6-dibromoaniline); poly[N1-(2,6- di(thiophenyl-2-yl)phenyl)benzene-1,4-diamine] and poly[aniline/2,6-di(thiophen-2-yl)aniline (1: 1)]),display selectivity towards iodide over other halides, with good reproducibility and sensitivity, asevidenced by the linear relationship between concentration vs generated current measured at a fixed-5 - potential. Limit of detection (LOD) lower than 7.3510 , limit of quantification (LOQ) below 7.4310 5 -1 2 molL and linear regression r > 0.99 were obtained. It is thus possible to develop with any of thesepolymers simple, very stable and inexpensive devices for the selective and direct quantification ofhalides, the most suitable being poly[N1-(2,6-di(thiophenyl-2-yl)phenyl)benzene-1,4-diamine], thatproduces the greatest current signals for iodide.