Self-assembled host-guest nanostructures on gold electrodes for thiodianiline determination

Self-assembled monolayers of thiolated β-cyclodextrins on a gold electrode have been developed for the determination of thiodianiline. Pentanethiol was employed to fill the empty space between the β-cyclodextrins on the surface. The formation of a 1:2 inclusion complex between thiodianiline and β-cyclodextrin was studied by electrochemistry. The parameters affecting the modification of the electrode and the determination of thiodianiline by square wave voltammetry were optimized. The limits of detection and determination are 190 and 205 μg L−1, respectively. The accuracy, in terms of relative error values, is <7%. The precision, in terms of RSD (for n = 5), is <5%. The method was applied to the determination of thiodianiline in real wastewater samples with RSD values of <11% and an average recovery of 98% for all the spiking levels assayed.