Highly sensitive methyl parathion electrochemical sensor designed from expired mung bean-derived porous carbon embellished with cerium oxide nanoparticles

Methyl parathion (MP) is one kind of highly toxic, efficient, and broad-spectrum organic phosphorus insecticides, which may prevent and control various pests on crops. However, the unscientific usage of MP has caused serious harm to humans and ecological environment. It is very necessary to design a sensitive and selective MP analysis method to ensure the food safety and life health. In this work, we reported a low-cost and environmental-friendly strategy to prepare the expired mung bean derived porous carbon (EMBPC) with interconnected carbon conductive network and large specific surface area, which was further decorated by cerium oxide (CeO2) nanoparticles. EMBPC possessed good conductivity property and electrochemical active area, which effectively boosted the charge transfer efficiency. CeO2 nanoparticles with good biocompatibility and high catalytic capacity promoted the efficient adsorption of MP on the surface of sensing electrode due to the affinity of CeO2 nanoparticles towards the phosphate groups of MP. Furthermore, EMBPC with porous carbon conductive structure could effectively make up for the inherent disadvantage of CeO2 nanoparticles in the term of electrical conductivity. The fabricated EMBPC@CeO2/GCE sensor showed highly sensitive MP detection property with low limit of detection (LOD) of 9.028 nM. The satisfactory repeatability, reproducibility, and anti-interference ability could be achieved at the fabricated MP electrochemical sensor. For the detection of MP in food samples, the EMBPC@CeO2/GCE sensor showed satisfactory recovery rates of 95.25–112.31 % and low RSD of 1.76–4.05 %, which suggested the good application prospect of the EMBPC@CeO2/GCE sensor.