Research On The Preparation And Application Of CuS Nanomaterials Based On The Biotemplated Method

Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli)are the most common infectious bacteria in our daily life,and seriously affect human's health.Due to the frequent and extensive use of antibiotics,the microbial strains forming drug-resistance have become more and more difficult to deal with.Compared with antibiotics,antibacterial nanomaterials have different sterilization mechanisms and can reduce the emergence of multidrug-resistant bacteria.Copper sulfide nano-materials have gradually become the most prominent antibacterial nanomaterials due to their low biotoxicity,simple synthesis method and high thermal stability.Herein,we utilized bovine serum albumin(BSA)as the template to synthesize uniform copper sulfide(CuS)nanoparticles via a biomineralization method.The as-prepared BSA-CuS nanocomposites showed good biocompatibility and strong near-infrared absorbance performance and can be used as an efficient photothermal conversion agent for pathogenic bacteria ablation with a 980 nm laser at a low power density of 1.59 W/cm2.The cytotoxicity of BSA-CuS nanocomposite was investigated using skin fibroblast cells and displayed good biocompatibility.Furthermore,the antibacterial tests indicated that BSA-CuS nanocomposite showed no antibacterial activity without near infrared(NIR)irradiation.In contrast,they demonstrated satisfying killing bacterial ability in the presence of NIR irradiation.Interestingly,S.aureus and E.coli showed various antibacterial mechanisms,possibly owing to the different architectures of bacterial walls.Considering the low cost,easy preparation,excellent biocompatibility and strong photothermal convention efficiency(24.68%),the combination of BSA-CuS nanocomposites and NIR irradiation will find promising application on the treatment of antibiotics-resistant pathogenic bacteria.It is well known,in the polluted wastewater that there are mainly organic aromatic compounds with high COD,high color contents,and solubility,and obvious chroma even at very low concentrations.Furthermore,the wastewater has strong toxicity and carcinogenicity.Crucially,the complex molecular structure of dye makes it difficult to remove in the condition of heat,light,microbes and even oxidants.Therefore,it is urgent to find a green,efficient method to remove organic dye from wastewater.In the second part of this work,diatomite supported copper sulfide nanomaterial is applied in photocatalytic degradation of methyl orange and methylene blue.Copper sulfide nano-materials uniform loading on the surface of diatomite has increased the active site of the catalyst,which can catalyze the hydrogen peroxide to oxidizing OH·radicals under natural light.This OH· radical can effectively destroy the molecular structure of organic matter,thus achieving the purpose of water treatment.At the same time,the diatomite can adsorb the organic matter in the wastewater to it's surface by physical adsorption,which further increased the chance of contact with OH-radicals.Colorimetric experiment(3,3',5,5'-Tetramethylbenzidine,TMB)shows that copper sulfide can be used as catalyst to oxidize colorimetric substrates.Therefore,copper sulfide supported on the diatomite will open an avenue for photocatalytic degradation of organic pollutants and research on peroxidase-like activity.