title: Enhancing the antimicrobial activity of natural extraction using the synthetic ultrasmall metal nanoparticles.
abstract: The use of Catechin as an antibacterial agent is becoming ever-more common, whereas unstable and easy oxidation, have limited its application. A simple and low-energy-consuming approach to synthesize highly stable and dispersive Catechin-Cu nanoparticles(NPs) has been developed, in which the stability and dispersivity of the NPs are varied greatly with the pH value and temperature of the reaction. The results demonstrate that the optimal reaction conditions are pH 11 at room temperature. As-synthesized NPs display excellent antimicrobial activity, the survival rates of bacterial cells exposed to the NPs were evaluated using live/dead Bacterial Viability Kit. The results showed that NPs at the concentration of 10 ppm and 20 ppm provided rapid and effective killing of up to 90% and 85% of S. aureus and E. coli within 3 h, respectively. After treatment with 20 ppm and 40 ppm NPs, the bacteria are killed completely. Furthermore, on the basis of assessing the antibacterial effects by SEM, TEM, and AFM, it was found the cell membrane damage of the bacteria caused by direct contact of the bacteria with the NPs was the effective mechanism in the bacterial inactivation.
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China.
authors.forename: Huanhuan
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China.
authors.forename: Quansheng
authors.initials: Q
authors.lastname: Chen
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China.
authors.forename: Jiewen
authors.initials: J
authors.lastname: Zhao
authors.affiliation: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, P.R. China.
authors.forename: Khulal
authors.initials: K
authors.lastname: Urmila
mesh_terms: D002392:Catechin / Q000737:chemistry* / Q000494:pharmacology / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D003300:Copper / Q000737:chemistry; D004337:Drug Carriers / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D013211:Staphylococcus aureus / Q000187:drug effects; D013696:Temperature
chemical_list: D004337:Drug Carriers; D003300:Copper; D002392:Catechin