| Nowadays,bacterial infections have posed a serious threat to public health.Although scientific researchers have made unremitting efforts in the field of antibacterial applications,they still cannot avoid the problems of bacterial resistance and large side effects on organisms.Therefore,the development of a highly effective and environmentally friendly antibacterial agent is currently the primary task.In recent years,the rapid development of nanotechnology has promoted the application of nanomaterials in biomedicine to extensive attention.As a typical two-dimensional nanomaterial,molybdenum disulfide(Mo S2)has the advantages of large specific surface area,wide spectral response,and narrow band gap.Because Mo is an indispensable trace element in the molecular structure of many enzymes,and S is a common component in proteins,Mo S2 has low toxicity and is regarded as one of the best choices for biological antibacterial materials.Metal nanoparticles can release metal ions to damage bacterial cell membranes.Compared with precious metals(gold,silver,etc.),copper nanoparticles(CuNPs)are more cost-effective.Based on this,this paper prepared CuNPs/Mo S2 composite material to achieve the synergistic antibacterial effect.The specific research work is as follows:(1)CuNPs were uniformly grown on the exfoliated Mo S2 surface by irradiation(UV:365nm).By optimizing the concentration of the Mo S2 dispersion,the concentration of the Cu Cl2solution,and the irradiation time,the size of CuNPs was controlled below 5 nm,which solved the problem of the naked CuNPs tending to agglomerate.Compared with Ag NPs/Mo S2prepared by solvothermal method,it is proved that this method can effectively reduce the size of nanoparticles.(2)Compared with single-component materials(CuNPs,Mo S2),the CuNPs/Mo S2composite material show significant inhibitory activity against Staphylococcus aureus(Gram-positive bacteria)and Escherichia coli(Gram-negative bacteria)(almost 100%bacterial killed).Through the investigation of the antibacterial mechanism,it is found that CuNPs/Mo S2 can synergistically generate reactive oxygen species(ROS)-hydroxyl radicals(·OH)with high oxidizing ability.At the same time,oxidative stress without reactive oxygen species(ROS)production can also cause damage to important components of bacteria and inactivate them.In addition,the Cu2+released by CuNPs has greater toxicity to bacteria.The antibacterial effect of the CuNPs/Mo S2 composite material can be further improved under 660 nm visible light irradiation.This research is expected to promote the deep-level development of nano-materials in the field of antibacterial applications. |
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