A novel pomegranate-inspired bifunctional electrode materials design for acetylcholinesterase biosensor and methanol oxidation reaction.

A pomegranate-inspired bifunctional electrode material based on Ni/NiO nanoparticle embedded in nitrogen-doped, partially graphitized carbon framework (Ni/NiO@NPGC) was designed and prepared for the construction of novel electrochemical biosensor and methanol oxidation reaction (MOR). Profiting from itsspecialstructureandfunction, Ni/NiO@NPGC was employed as a matrix immobilizing acetylcholinesterase (AChE) for methyl parathion (MP) sensor. The developed biosensor was proved to have wide linear range (1.0 × 10-14-1.0 × 10-8 g mL-1), low detection limit (3.5 × 10-15 g mL-1), and good stability for the determination of MP in practical samples. In addition, the Ni/NiO@NPGC electrode exhibited high electrocatalytic activity (specific activity 73.1 mA cm-2) and durability for the MOR in alkaline medium. The results were mainly attributed to the pomegranate-like architecture structure with pyridinic N and carbon frame of Ni/NiO@NPGC, which ensured the electrochemical activities of all nanoparticles and immobilization of enzyme. In addition, the metal oxide was well dispersed to prevent from self-agglomeration and kept mass transfer paths. The work provides a reference for the development of high-performance bifunctional electrode material for the biosensor and MOR.