Study On Peroxidase-like Activity Of Cerium Organic Framework Surported Pt Nanoparticles And Its Application

Peroxidase catalyzes the oxidation of its substrate with peroxide.So far,peroxidase has been widely applied in bioanalytical and clinical chemistry.The activity of peroxidase is lost after being exposed to extremes of pH and high temperature.To reduce time and cost of purification of enzymes,there is increasing interest in enzyme mimetics.Metal nanoparticles are more stable and retain their catalytic activity after exposed to a harsh environment.So the preparation of metal nanoparticles and the performance of artificial enzyme have been extensively studied.Most of the metal nanoparticles are prone to aggregation,so that the catalytic activity of particles is affected.In this work,Pt nanoparticles are deposited on cerium metal organic framework?CeMOF?with the aid of tip ultrasound and the interaction between the carboxy groups on the surface of CeMOF and Pt ions.CeMOF was chosed to be the surport because of it is stable and has a large surface area.CeMOF@Pt shows the activity of peroxidase.The catalytic activity of CeMOF@Pt was influenced by the size of Pt nanoparticles loaded.The smaller the size of the Pt particles,the higher activity it exhibited.Its catalytic activity is influenced by pH,temperature and H₂O₂ concentration.The optimal pH and temperature were approximately pH 4.0 and 35?.The kinetic parameters of CeMOF@Pt were determined.The results indicated that CeMOF@Pt has a higher affinity for TMB than for H₂O₂.A reaction system of CeMOF@Pt+H22O2+TMB+MNA was established and was applied for detecting nitroaniline.With the reaction system,the absorbance at 652 nm has shown linear response,when the concentration of nitroaniline changed from?3.125×10-4?1×10-2?mg/mL.The detection limit was 3.125× 10-4 mg/mL.With CeMOF@Pt as the catalyst,2,5-furandicarboxylic acid?FDCA?can be converted from oxidation of 5-hydroxymethylfurfural?HMF?under mild conditions.Under the optimum conditions,the conversion of HMF was close to 100%and the yield of FDCA was 95%after 12 h reaction at 70?.Consecutive use of CeMOF@Pt has demonstrated that CeMOF@Pt can be used to catalyze multiple cycles of HMF oxidation with a good recyclability.