Synthesis And Catalytic Application Of Nanomaterials With Intrinsic Peroxidase Activity

Within the development of material science,the technologies and materials of catalysis have been significantly developed.To develop new nanocatalysts and expand related applications,we synthesized the Ni/Fe layered double hydroxide?LDH[Ni^?-Fe^?]?and antimony doped tin oxide?ATO?nanomaterials.The intrinsic peroxidase properties of them have been investigated.Also,we demonstrated the application of these nanomaterials in analysis and catalytical degration.1.Three types of Ni/Fe-LDHs with different Ni/Fe ratio?3:1,4:1,5:1?were synthesized by using hydrothermal method and applied as peroxidase mimic.In this work,a new micro-sampling approach based on a syringe needle is developed;it was coupled with micro liquid-phase extraction to determine and quantify D-glucose in bananas.This sampling and extraction approach solved disadvantages of conventional sample pretreatment method usually involving mashing?blending or homogenization?,extraction,and dilution.The effects of solvent,solvent volume,and extraction time related to extraction were discussed.The results of this new detection method for D-glucose in fruits provided low limits of detection?0.025?g/mL?,wide linear range?0.1–3000?g/mL?and good linearity?r²=0.9998?.This work demonstrated a new and interesting approach for easy and efficient detection of analytes in raw fruit samples.2.In this work,Ni/Fe-LDHs used in previous project were utilized as peroxidase mimic.A new non-enzyme method based on hybridization chain reaction?HCR?and colorimetric reaction catalyzed by magnetic Ni/Fe-LDH nanosheets was developed for detection of micro RNA?miRNA?,let-7b.The DNA hairpins from HCR were separated and adsorbed by Ni/Fe-LDH.The peroxidase-like activity of Ni/Fe LDH was found to be enhanced by the DNA hairpins on the surface.The factors,such as ratio of Ni/Fe and concentration of DNA hairpins,related to the catalytic activity were evaluated and the mechanism was discussed.The results of this new detection method for let-7b provided low limit of detection?0.36 fM?,wide linear range?0.01 pM to200 pM?with good linearity?r²=0.9968?.The optimized method was applied to analyze let-7b in real samples,lung cancer cells.This work demonstrated a new and cost-effective approach for efficient detection of miRNA.3.ATO NPs with different Sb doping concentrations were synthesized by using hydrothermal method.Here,we shown that ATO nanoparticles?NPs?present an intrinsic peroxidase-like activity without any electro/photochemical assistance,which is generally required in many colorimetric detection processes.The ATO NPs'intrinsic peroxidase-like activity is first reported.The factors,such as Sb doping amount,pH and concentration of Na⁺ion related to the catalytic activity were evaluated and the mechanism was discussed.This work demonstrates that ATO NPs,which are composed of main group elements,have a good potential as a HRP mimic.4.In this work,we studied the fenton-like activity of ATO NPs with H₂O₂ and UV assistance.The factors which influence the ATO NPs'fenton-like activity,such us amount of doped Sb,pH and H2O2 concentration were investigated.The possible mechanism of ATO NPs'fenton-like activity was discussed based on the results from XPS and capture experiments.This work demonstrated that ATO NPs'high efficiency of MB degradation and good potential in practical application.