Electrochemical sensor based on graphene doped gold nanoparticles modified electrode for detection of diethylstilboestrol

An electrochemical sensor for detection of diethylstilboestrol (DES) was successfully developed. At first, graphene-modified glassy carbon electrode (Gr/GCE) was fabricated by casting graphene (Gr) on the surface of the pretreated glassy carbon electrode (GCE). Then, gold nanoparticles (Nano-Au) were produced by reducing gold chloride tetrahydrate (HAuCl4) employing cyclic voltammetry (CV). Electrochemical behavior of DES at the graphene doped gold nanoparticle modified glassy electrodes (Gr/Nano-Au/GCE) was studied and a new method was developed for the electrochemical analysis of DES. Gr/Nano-Au/GCE showed a good catalytic performance for the electrochemical oxidation of DES in pH = 6.0 phosphate buffer solution (PBS). The oxidation peak currents of DES showed a linear relationship with their concentrations in the ranges of 1.20 × 10−8-1.20 × 10−5mol L−1. The estimated detection limit is 9.80 × 10−9 mol L−1. When the relative error is less than ±5%, no interference was found when detection was performed in the presence of some common ions, estradiol, estriol, estrone and folic acid. The modified electrode has good selectivity and stability and has been successfully applied to the detection of DES in food samples.