Reduced Graphene Oxide Supported Cobalt Bipyridyl Complex for Sensitive Detection of Methyl Parathion in Fruits and Vegetables

Herein, we are described a green route to prepare reduced graphene oxide supported cobalt inorganic complex nanocomposite (GRGO/[Co(bpy)3]) (bpy=2, 2′-bipyridine) through facile and wet chemical approach. The formation of the nanocomposite was confirmed through suitable physical and chemical characterization techniques. The GRGO/[Co(bpy)3] nanocomposite was coated on the pretreated glassy carbon electrode (GCE). The GCE/GRGO/[Co(bpy)3] modified electrode has excellent electrocatalytic ability towards methyl parathion reduction, while the overpotential drops drastically to –0.18 V (vs. Ag/AgCl). Moreover, the effect of concentration, scan rate and electrolyte pH were detail studied. Besides, the linear response range was 0.05-1700 μM and the detection limit was 0.0029 μM (S/N=3) and the sensitivity was 1.8197 μA μM−1 cm−2. Moreover, the fabricated electrode has high level of selectivity, which delivers satisfactory repeatability, reproducibility and stability. The sensing method was successfully demonstrated in real samples such as, tomato and apple samples.