Study On The Preparation And Peroxidase-like Activity Of Cu_1-xZn_xS Nanoparticles

The new nanoenzyme synthesized from nanomaterials has the advantages of low cost and easy storage,and can be widely used in biosensing,biotherapy,and environmental engineering,etc.field.However,the preparation of nanoenzymes with high catalytic activity is affected by synthetic materials and methods,so enhancing the catalytic activity and selectivity of nanoenzymes is still the focus of research on nanoenzyme synthesis technology.Among them,copper sulfide,as an important narrow band gap p-type semiconductor nanomaterial,can produce excellent absorption characteristics in the near-infrared region due to the d-d transition of Cu²⁺itself,and its photothermal effect has attracted widespread attention.Through the method of doping ions in copper sulfide crystals,the internal carrier transport rate can be changed,and its photothermal effect can help to enhance the catalytic properties of nanoenzymes.Therefore,the limitations in practical applications caused by the poor stability of natural enzymes can be improved.In addition,copper sulfide nanomaterials have good biocompatibility.By compounding with surfactants and other materials,the dispersibility of copper sulfide in the solution can be improved,and the problem of easy agglomeration of metal materials can be solved,and it can be better applied to catalysis,photothermal therapy,as well as the field of photodynamic therapy.Based on the above analysis,how to enhance the catalytic properties of copper sulfide nanoparticles,and build a biosensor that can quickly detect glutathione and enhance photodynamic therapy,conducted the following research:（1）Using copper chloride,zinc acetate and sodium citrate as raw materials,spherical Cu_1-xZn_xS nanoparticles with a diameter of about 11 nm were prepared by the water bath method,and the influence of Zn²⁺doping on the synthesis of the material and the peroxide-like The effect of enzyme catalytic activity.When the doped zinc ion enters the copper sulfide crystal,the lattice structure of the copper blue phase copper sulfide is not destroyed,and the internal carrier migration rate is enhanced.The hydrogen peroxide in the solution is catalytically decomposed into hydroxyl radicals at the active sites on the copper sulfide surface.The substrate TMB is oxidized to ox TMB by the hydroxyl radicals.The color of the solution changes from colorless to blue.Cu_1-xZn_xS nanoparticles show Excellent peroxidase-like activity.Glutathione can reduce ox TMB to TMB.Based on the above analysis,sensitive colorimetric detection of glutathione can be performed by detecting the absorption spectrum of ox TMB.（2）The surfactant poly-vinylpyrrolidone（PVP）and Cu_1-xZn_xS nanoparticles are combined to form Cu_1-xZn_xS/PVP nanocomposites.Using the peroxidase-like activity of the Cu_1-xZn_xS/PVP nanocomposites to decompose hydrogen peroxide into oxygen and hydroxyl radicals,PVP can enhance the catalytic activity of the composite.Under the action of copper sulfide,oxygen can be excited into singlet oxygen.By detecting the absorption spectrum of1,3-diphenylisobenzofuran（DPBF）,it is proved that the composite material has a photodynamic effect.