Preparation Of Precious Metal/UiO-66 Nano-enzyme And Its Application In Biomolecular Detection

Noble metal nanoenzymes have broad application prospects in the chemical and biological fields due to their simple preparation,controllable morphology,easy modification of the surface,and environmentally friendly and harmless advantages,but they are faced with how to achieve their high catalytic efficiency and stability.Two major issues.In this paper,metal-organic frameworks(MOFs)are used as ideal carriers to confine and induce the formation of well-dispersed ultra-small precious metal nanoparticles to improve the catalytic efficiency and stability of precious metal nanoenzymes,construct precious metal/MOFs composite nanomaterials,and The mechanism and environmental dependence of its catalytic process have been explored,and the detection platform of biomolecules has been established using its enzyme-like activity.The main contents of the research are as follows:1.Using UiO-66 as a carrier to synthesize ultra-small Pt nanoparticles:A zirconium-based metal organic framework(UiO-66)with good chemical stability and high porosity was synthesized by hydrothermal method.In the process,By changing the molar ratio of organic ligand terephthalic acid to zirconium ion and the reaction temperature and time,optimized conditions can be obtained.The prepared UiO-66 has uniform size(about 500nm)and good dispersion,and is used to construct Pt/UiO-66 nanocomposites.By adjusting the added amount of Pt Cl₄^2-,the percentage of Pt in UiO-66 can be easily adjusted.Due to the restriction of the mesopores of the carrier UiO-66,the Pt particles with an average diameter of3.8 nm were formed by chemical reduction with a reducing agent,which were uniformly dispersed in the pores of the carrier UiO-66.Tests found that Pt/UiO-66 composite nanomaterials have high-efficiency oxidase-like and peroxidase-like activities.The activities of oxidase-like and peroxidase-like enzymes all depend on the percentage of Pt.In addition,the optimal p H of the reaction is 4 and the optimal temperature is 40?;the addition of the carrier UiO-66 improves the utilization efficiency and stability of Pt nanoparticles,and provides more active sites for the catalytic reaction.The efficiency is 3.9 times that of commercial Pt/C.Using the peroxidase-like activity of Pt/UiO-66,a colorimetric method that can be used for actual blood glucose detection was established,and the blood glucose was specifically detected with a detection limit of 0.033 m M.2.In order to explore whether the carrier UiO-66 has the same effect on other precious metals,UiO-66 is used as the carrier to synthesize ultra-small Au nanoparticles:Based on the above experimental method,Au/is prepared by using Au Cl₄^-instead of Pt Cl₄^2-The UiO-66composite nano material keeps Au in the entire UiO-66 and also maintains an ultra-small size and good distribution,with an average diameter of 7.0 nm.The test found that Au/UiO-66 is different from Pt/UiO-66.Au/UiO-66 has only strong peroxidase-like activity,but weak oxidase-like activity.In addition,the optimal p H of the reaction is 6,and the optimal temperature is 50?,and the catalytic efficiency of Au/UiO-66 is significantly stronger than that of the commercial PVP-protected Au ball catalyst.Utilizing the peroxidase-like activity of Au/UiO-66,a sensitive and selective detection platform has been established,which can be used to determine the concentration of glucose(with a detection limit of 0.033 m M),as well as organisms that can affect the activity of Au/UiO-66 enzymes.Molecules such as:dopamine(detection limit is 0.0022 m M),HS^-(detection limit is 0.0016 m M)and so on.In summary,we successfully prepared UiO-66 with good chemical stability and high porosity,and used it as an ideal carrier for confining and inducing the formation of well-dispersed ultra-small noble metal nanoparticles,and prepared Pt/UiO-66 and Au/UiO-66greatly improve the catalytic efficiency and stability of precious metal nanoenzymes Pt and Au.