| At present,the emergence of multi-drug resistant bacteria due to excessive or unreasonable use of antibiotics poses a serious threat to human life and health.There is an urgent need to develop new and efficient new technologies that do not produce bacterial resistance.Near-infrared photothermal antibacterial technology is a new type of antibacterial technology developed in recent years that is fast,efficient,and does not produce drug resistance.It mainly depends on the development of photothermal nanomaterials.Gold-based nanostructures are widely used as photothermal agents due to their strong near infrared absorption and good biocompatibility.However,most gold-based nanostructures require the use of organic templates or surfactants during the synthesis process.The surface contains a large number of highly toxic surfactants,which must be further modified to use.It's not only increase the cost,but also remain organic surface active agents that are still potentially biologically toxic.Therefore,it is of great research significance to develop new methods that are convenient,green and have good biocompatibility,high light-to-heat conversion efficiency,and strong interaction with bacteria to obtain gold-based nanostructures.In this paper,by regulating the assembly of biological macromolecular lysozyme to form ultra-fine nanofibers with stable structure,using this as a template,it uses its one-dimensional ultrafine structural confinement effect to regulate the formation of ultra-small Au/Cu bimetallic nanoparticles,and it is used in the research of photothermal antibacterial applications,providing new ideas for the synthesis of new gold-based photothermal nanomaterials with high biological safety,high photothermal conversion efficiency and strong interaction with bacteria.The specific research contents are as follows:Controlled synthesis of lysozyme nanofibers by using acid incubation method and eutectic solvent method.Firstly,the acidic solution with p H=2 and the eutectic solvent with 5%by volume was prepared,then added it to the acidic solution of the control group with p H=2.Secondly,the lysozyme incubation time of the lysozyme powder dissolved in different solvents was controlled,and then the one-dimensional ultrafine lysozyme nanofibers were obtained when the reaction time is 7 h.Finally,AFM,CD,FTIR,TEM and other technologies were used to compare and analyze the lysozyme nanofibers prepared by the two methods.Using the biomimetic mineralization method,the biocomposite gold nanoparticles combined lysozyme nanofibers(LNFs@Au)were synthesized under the condition of37?with lysozyme as templates,in which the gold nanoparticles had a particle size of 3.94 nm and a light-to-heat conversion efficiency of 31.89%.Under the conditions of 2 Wcm-2 and 1.2 m M concentration,808 nm light irradiation for 10 min killed Gram-negative bacteria E.coli and Gram-positive bacteria S.aureus and the antibacterial efficiency of the material also reached 100%.In addition,the material was found to have strong bacterial adhesion,further enhancing the antibacterial efficiency.By introducing copper components and using lysozyme nanofibers as templates,copper-gold@lysozyme bimetallic nanofibers(LNFs@Au/Cu)were synthesized,which can not only reduced the gold content,but also used copper electrons in the d-d orbit.The transition effectively enhanced the absorption of its near-infrared light,thereby achieving the enhancement of photothermal antibacterial efficiency.Au/Cu@LNFs were obtained under mild reaction conditions have enhanced antibacterial properties against E.coli using enhanced photothermal properties. |
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