Multifunctional integration of biomass-derived porous carbon and zirconium dioxide for electrochemical sensing analysis of methyl parathion

We developed an economical and environment -friendly technique for preparing the expired mung bean -derived porous carbon (EMBPC), which possessed large specific surface area and 3D interlinked carbon conductive network. Zirconium dioxide (ZrO2) nanoparticles were further incorporated into the porous structure of EMBPC to form the EMBPC@ZrO2 composite, which was served as electrode sensitizer for the fabrication of EMBPC@ZrO2/GCE sensor. EMBPC exhibited superior conductivity property and large electroactive area, which helped enhance the charge transfer efficiency between electrolyte and sensing electrode. ZrO2 nanoparticles with good biocompatibility achieved the efficient adsorption of methyl parathion (MP) owing to the recognition of ZrO2 towards the phosphate groups of MP. Furthermore, EMBPC with porous carbon conductive structure could make up for the inherent disadvantage of ZrO2 nanoparticles in the term of electrical conductivity. The EMBPC@ZrO2/GCE sensor achieved the highly sensitive MP detection (LOD: 8.77 nM) in linear MP concentration range of 0.01-10 mu M. The satisfactory practical property was realized at the EMBPC@ZrO2/GCE sensor with satisfactory recovery rates of 91.95-124.72% and low RSD% of 1.21-3.35% for the electrochemical detection of MP in food samples.