Sodium Dodecyl Sulfate Doped Polyaniline for Enhancing the Electrochemical Sensitivity of Mercury Ions

Polyaniline (PANi) was electro-synthesized on the surface of screen-printed carbon electrodes in the presence of sodium dodecyl sulfate (SDS) as a dopant. The complex of aniline and SDS created a conductive (PANi-SDS) film at lower aniline concentration. The PANi-SDS film contained negative charge due to the anionic head of SDS. The PANi-SDS modified electrode was integrated into a poly(dimethylsiloxane) microfluidic chip as an electrochemical sensor for mercury detection. The presence of SDS in the polyaniline film enhanced the possibility of mercury ions uptake, and therefore, increased the peak current of square wave anodic stripping in the mercury detection. The mercury sensor exhibited a dynamic range from 6 to 35nM with detection limit of 2.4nM.