The Synthesis And Antibacterial Properties Research Of Noble Metal Nanoclusters

The relationship between humans and microorganisms is very complicated,and pathogenic microorganisms have a great impact on human health.Bacteria,viruses and fungi are common types of pathogens.The widespread use of clinical antibiotics is likely to increase the drug resistance of bacteria and other microorganisms,and the production process of antibiotics is complicated and the production equipment requirements are high.Therefore,substances with simple production process,low cost,and universal antibacterial effect are in urgent need of research and development.In recent years,studies have proposed that metal nanoclusters with ultra-small nanometer sizes(<2 nm)have excellent antibacterial properties.In this paper,the gram-negative bacterium E.coli K12 and the gram-positive bacterium Staphylococcus aureus are used as the research objects to prepare composite materials based on metal nanoclusters and develop new antibacterial nanomaterials.The results are as follows:With the help of different organic ligands,using tetrachloroauric acid as the metal core source,using hydrothermal method and microwave-assisted synthesis technology,successfully synthesized four different ligand-protected gold clusters: glutathione gold Nanoclusters(GSH-Au NCs),bovine serum albumin templated gold nanoclusters(BSA-Au NCs),ovalbumin templated gold nanoclusters(OVA-Au NCs),lysozyme templated gold nanoclusters(LZ-Au NCs).E.coli K12 was used as the experimental object to evaluate the antibacterial properties of the above four gold nanoclusters.The research results show that the antibacterial performance of metal nanoclusters not only depends on its ultra-small nanometer size,but also the type of ligand will have a great influence on its antibacterial performance.The LZ-Au NCs with lysozyme as the synthesis template showed the most excellent antibacterial properties.A rapid preparation method of gold-silver bimetallic nanoclusters is proposed.Using microwave-assisted circulation heating synthesis method,using lysozyme as template,tetrachloroauric acid and silver nitrate as metal seeds,silver-doped gold nanoclusters(LZ-Au Ag NCs)were synthesized.On the basis of LZ-Au Ag NCs,the photosensitizer methyl violet(CV)was added to prepare the CV/LZ-Au Ag NCs.The experimental results show that CV/LZ-Au Ag NCs can effectively kill E.coli K12 and S.aureus,and has a broad-spectrum antibacterial ability.Further explored the antibacterial mechanism of CV/LZ-Au Ag NCs,and found that CV/LZ-Au Ag NCs synergistically kill bacteria by breaking cell membranes and increasing oxygen free radicals.Based on the CV/LZ-Au Ag NCs solution,a CV/LZ-Au Ag NCs functionalized antibacterial silica gel material with excellent antibacterial properties was prepared,which provides a new solution for the research of antibacterial surface materials.