A sensitive electrochemical sensor based on the expired soybean-derived porous carbon for the determination of methyl parathion

In this work, a sensitive electrochemical sensor was designed by using the expired soybean-derived porous carbon (ESBPC) as electrode sensitizer, which was used to modify the glassy carbon electrode (GCE). The fabricated ESBPC/GCE sensor was successfully applied for the electrochemical detection of methyl parathion (MP). ESBPC was prepared by hydrothermal carbonization followed with high temperature potassium hydroxide (KOH) activation process. The obtained ESBPC sample presented obvious porous morphology, which could contribute to the improvement of charge transfer efficiency due to the interconnected porous carbon structure. Moreover, the porous morphology significantly increased the specific surface area of ESBPC, which promoted the improvement of adsorption capacity of carbon material towards MP molecules. As a result, the ESBPC sample presented high electrical conductivity and good adsorption capacity, which contributed to the improvement of electrochemical sensing performance. When used for the detection of MP, the ESBPC/GCE sensor presented sensitive MP determination performance with low limit of detection (LOD) of 11.7 nM (MP concentration: 0.05–10 μM). The DPV curve of ESBPC/GCE sensor showed obvious characteristic cathodic peak at − 0.12 V (vs. Ag/AgCl). The low relative standard deviation (RSD) of 0.6–1.2% could be obtained for the reproducibility and repeatability measurements, suggesting the good reproducibility and repeatability of the fabricated ESBPC/GCE sensor. In addition, the good anti-interference performance could be achieved with low RSD value of 2.6% at the ESBPC/GCE sensor.