We present an electrochemical sensor towards 4,4'-oxydianiline (Oxy) determination based on the ability of MoS 2 for diamine adsorption and preconcentration. It consists of a glassy carbon electrode covered by drop-casting with MoS 2 nanosheets obtained by exfoliation in 45% EtOH/H 2 O mixture. X-Ray Photoemission Spectroscopy indicates that Oxy accumulates on the MoS 2 surface through an electropolymerization process similar to that reported for aniline. We use both, electrochemical impedance spectroscopy and atomic force microscopy for the characterization of the electrode surfaces at the different stages of the device fabrication. The electrochemical sensor allows the detection of Oxy at 8 ×10 -8 M level with Er (%) and RSD (%) values lower than 8.3 and 5.6, respectively, in all the concentration range assayed. The methodology proposed was applied to the selective Oxy determination in real river water samples, showing very good selectivity and recoveries of around 95% in average.
KeynotesTransition metal dichalcogenides; electrochemical detection; 4-4´Oxydianiline preconcentration; X-ray photoemission spectroscopy; atomic force microscopy