Preparation Of CeO₂ Nano-enzyme And Its Application In Degradation And Detection Of Organic Pollutants

In this paper,the hollow ball,flower ball and block three different morphology of cerium oxide nanomaterials were prepared by hydrothermal method.The three kinds of materials were characterized by X-ray diffraction?XRD?and scanning electron microscopy?SEM?.The properties of the oxidase were measured by TMB colorimetric method.The results indicated that the three kinds of CeO₂ had the characteristics of oxidase,and the activity of hollow ball cerium oxide was higher.Choosing high enzyme activity of hollow ball CeO₂ as the research object,The performance of CeO₂ nano-enzyme catalytic degradation p-nitrophenol was discussed.It was found that under the condition that the pH of solution system was 5.0,the dosage of CeO₂ nano-enzyme was 40 mg,the initial concentration of p-nitrophenol was 20mg/L,the reaction time is 2h and the reaction temperature was 30 ?,the catalytic degradation rate of p-nitrophenol by CeO₂ nanoparticles reached 78%.Using hollow ball CeO₂ nano-enzyme and aptamer,The single-minded and visualization detection platform of organic pollutants in water was constructed,and the influence factors of the platform was optimized.The optimized conditions were as follows: 10 mg CeO₂ nanomaterials,2 mL TMB coloration liquid,the color development time was 20 min,the concentration of sodium chloride was 150 nmol/L,the dosage of the aptamer was 3 mL,and the adsorption time of the aptamer and CeO₂nano-enzyme was 15 min.Selecting kanamycin as the application object,the sensitivity and specificity of the platform was verified.The results showed that the minimum detection molar concentration of kanamycin was 100 nmol/L,and erythromycin,azithromycin and tetracycline were selected as interfering antibiotics.The study proved that the platform had good specificity.