An electrochemical platform for guanosine-5' -monophosphate detection using gold doped polypyrrole nanocomposite embedded on graphitic carbon nitride

In this study, an electrochemical platform based on a novel ternary nanocomposite of advantageously united gold nanoparticles, polypyrrole and graphitic carbon nitride (Au-PPy@g-C3N4) for detection of guanosine-5'-monophosphate (GMP) was designed. Owing to the 7C-7C stacking interaction between the ring structures of the nucleobases in GMP and the hexagonal cells original from g-C3N4 in Au-PPy@g-C3N4, the irreversible oxidation of GMP occurred with the potential of 1.08 V (vs. SCE) in phosphate buffer solution (PBS). Under the optimized conditions, the peak currents were linear with the concentration of GMP ranging from 0.05 to 200 mu g.mL(-1) with a detection limit of 0.028 mu g.mL(-1) (S/N=3). Meanwhile, the Au-PPy@g-C3N4/APTES/GCE sensor exhibited good stability, high reproducibility and acceptable anti-interference ability. Importantly, the results of the detection of GMP with the proposed sensor were well consistent with the data determined by high performance liquid chromatography (HPLC), indicating a promising platform for evaluation of soup quality.