The Preparation,Characterization And Peroxidase Activity Study Of Iron Molybdate And Cerium Vanadate With Different Morphology

Enzymes play key roles in a lot of chemical reactions.However,they are hard to be used extensively because of their protein or RNA nature,high requirements for catalyzing environment and difficulty in extraction and purification.Therefore,artificial enzyme mimics are the potential substitute for native enzyme owing to their ease of preparation,low cost,high stability and catalytic activity.Peroxidase mimics have received extensive attention for their significance in H₂O₂ and glucose detection.In this work,four morphologically different iron molybdate nanomaterials and four morphologically different cerium vanadate nanomaterials were prepared through the hydrothermal synthesis method under different reaction conditions.They were named Fe₂?MoO₄?₃-F?Flower like?,Fe₂?MoO₄?₃-P?Plate like?,Fe₂?MoO₄?₃-B?Butterfly like?,Fe₂?MoO₄?₃-S?Sphere like?and CeVO₄-1.5?pH = 1.5?,CeVO₄-2?pH = 2?,CeVO₄-2.5?pH = 2.5?,CeVO₄-3?pH = 3?,respectively.The morphology,composition,specific surface area and Zeta potential of these prepare namomaterials were measured TEM,FESEM,XRD,XPS,EDX,BET,and Zeta potential determination.As a result,Fe₂?MoO₄?₃-F and Ce VO4-2 showed the largest specific surface area,better peroxidase activity and reusuability.Through the study of parameters affecting the peroxidase activity of these nanomaterials we find that material concentration,H₂O₂ concentration,reaction temperature and pH will influence the nanomaterials' peroxidase activity.The best Fe₂?MoO₄?₃-F and H₂O₂ concentration,reaction temperature and pH for Fe₂?MoO₄?₃-F are 300 ?g/mL,2.0 mM,25 °C and 4.0,respectively.And the best CeVO₄-2 and H₂O₂ concentration,reaction temperature and pH for CeVO₄-2 are 300 ?g/m L,2.0 mM,25 °C and 4.0,respectively.Through catalytic mechanism experiment,we find that Fe₂?MoO₄?₃-F and CeVO₄-2 catalyze the substrates via a Ping Pong mechanism.Based on our results,we built a visual detection system based on the excellent peroxidase activity of Fe₂?MoO₄?₃-F and CeVO₄-2 nanomaterials and the detection limit for H₂O₂ could be as low as 0.7 and 0.07 ?M,respectively.This work has not only provided a rapid,cheap,simple and sensitive method for H₂O₂ detection,but laid the foundation for developing new high-efficiency mimetic enzymes.