| Nanometer antibacterial technology are developed rapidly in recent years and have widely application prospects. Nano-silver is an important type of the nanometer antibacterial agents, which is an intense field of research because of it has the advantages of strong antibacterial effect,broad antibacterial spectrum, and no drug resistance. Some developed countries began manufactured products with antibacterial activity by using the nano-silver. In this paper, chemical reduction has been used for preparation the colloid silver nano-particles, and we present a simple method to fabricate stainless steel-based antimicrobial composites by fixing silver nano-particles onto the surface, which has wide-ranging usage. Then we discuss the antibacterial rate, mechanism and Application security of the preparation material.First, ethylene glycol was used as the reductant and solvent and PVP was the surface protectant for preparation colloid of the silver nano-particles(AgNPs). We have utilized X-ray diffraction(XRD), Transmission electron microscope(TEM) and dynamic light scattering(DLS) to characterized the silver nano-particles obstained. The result show that face-centered phase of AgNPs and the mean diameter distribution ranged from 18～40nm. Briefly, the stable state and uniform grading of AgNPs may specially attribute discuss antibiogram of the AgNPs and coating with the surface of Test Materials for next step.AgNPs were covalently assembled on the surface of 304L stainless steel by using silane-bond of (3-aminopropyl)triethoxysilane(APTES) as the coupling agent. After 15d immerse into acid and base solution with high temperature, the release of silver were hardly any, as measured by ICP-OES. With scanning electron microscopy (SEM) to look the surface of silver coated stainless steel(AgSS), tested with 8strains of familiar microbe, by film attachment method. The result show that the bactericidal rate are greater than 96% to all tested microbial, combining the low cost and high effectiveness, such composites are expected to be useful as antimicrobial materials. Moreover, we researched inhibitory effect of AgSS on biofilm formation on its surface, the adhesion and propagation of microbe were evidently reduced by nano-silver coated stainless steel, thereby the biofilm was prevented before it formation, however a mount of bacteria on the surface of blank stainless steel, and we can observed the morphology of biofilm on SEM images. At the process of the bacterial suspension interaction with AgSS, after adding 5 mM L-Cys in suspension, he AgSS antibacterial rate to P.aeruginosa and B.subtilis reduced to 70.6%,58.2% after 4h, result of paper chromatography analysis that the structure of cysteine must be destroyed, indicated the sample possibly has the ability of oxidation of which obtain sulfhydryl group. The SEM image showed that the morphology of microbe was changed a lot after contacting with AgSS, cell walls were destroyed and protein and K+ and other important things in the cells were outflow. There was no phenomena of dispersion after gel electrophoresis of DNA extracted from experiment strain contacting with AgSS.To evaluate the safety of use nano-silver, when the oral does of AgNPs for mice is 5000mg/kg, mice were safety; the rate PCE micronucleus cell induced by 2 dosages have no Statistical significance while compared with the negative group of distilled water(P>0.05). That indicated AgNPs belonged to practical non-toxic grade, and we didn't find the mutagenesis on mice bone marrow PCE.
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