Composites of thiol-grafted PEDOT with N-doped graphene or graphitic carbon nitride as an electrochemical sensor for the detection of paracetamol

A novel electrochemical sensor with thiol-grafted PEDOT/ N -doped graphene ( N -Gr/PEDOT-MeSH) and thiol-grafted PEDOT/graphitic carbon nitride (g-C 3 N 4 /PEDOT-MeSH) composites was fabricated for the detection of paracetamol (PAR). The formation mechanism of the obtained structure was thoroughly studied. And from the electrochemical results, the synergistic effect between the PEDOT-MeSH and g-C 3 N 4 or N -Gr improved the electron transfer and conductivity of the modified electrodes and enhanced the sensing responses toward the electrochemical oxidation of PAR. The calibration curve of N -Gr/PEDOT-MeSH and g-C 3 N 4 /PEDOT-MeSH composites exhibited the wider linear responses for PAR, ranging from 2 to 1680 µM and 0.4 to 1280 µM, and the detection limits ( S / N  = 3) were 1.42 µM and 1.0 µM, respectively. Furthermore, the obtained composites exhibited the excellent reproducibility, lower detection limit and good stability. And it was capable of detecting PAR in real samples with a satisfying result.