Centre for Nano-Biotechnology, School of Bio-Sciences and Technology, VIT University, Vellore, India.
Colloids Surf B Biointerfaces. 2011 Oct 1;87(1):129-38. doi: 10.1016/j.colsurfb.2011.05.012. Epub 2011 May 12.
Silver nanoparticles (SNPs) are being increasingly used in many consumer products like textile fabrics, cosmetics, washing machines, food and drug products owing to its excellent antimicrobial properties. Here we have studied the adsorption and toxicity of SNPs on bacterial species such as Pseudomonas aeruginosa, Micrococcus luteus, Bacillus subtilis, Bacillus barbaricus and Klebsiella pneumoniae. The influence of zeta potential on the adsorption of SNPs on bacterial cell surface was investigated at acidic, neutral and alkaline pH and with varying salt (NaCl) concentrations (0.05, 0.1, 0.5, 1 and 1.5 M). The survival rate of bacterial species decreased with increase in adsorption of SNPs. Maximum adsorption and toxicity was observed at pH 5, and NaCl concentration of <0.5 M. A very less adsorption was observed at pH 9 and NaCl concentration >0.5 M, there by resulting in less toxicity. The zeta potential study suggests that, the adsorption of SNPs on the cell surface was related to electrostatic force of attraction. The equilibrium and kinetics of the adsorption process were also studied. The adsorption equilibrium isotherms fitted well to the Langmuir model. The kinetics of adsorption fitted best to pseudo-first-order. These findings form a basis for interpreting the interaction of nanoparticles with environmental bacterial species.
由于其出色的抗菌性能，纳米银颗粒（SNPs）越来越多地被应用于各种消费品，如纺织面料、化妆品、洗衣机、食品和药品。在这里，我们研究了 SNPs 对细菌的吸附和毒性，如铜绿假单胞菌、藤黄微球菌、枯草芽孢杆菌、巴氏芽孢杆菌和肺炎克雷伯菌。在酸性、中性和碱性 pH 值以及不同盐（NaCl）浓度（0.05、0.1、0.5、1 和 1.5 M）下，研究了 ζ 电位对 SNPs 在细菌细胞表面吸附的影响。随着 SNPs 吸附的增加，细菌的存活率下降。在 pH 值为 5 和 NaCl 浓度<0.5 M 时，观察到最大的吸附和毒性。在 pH 值为 9 和 NaCl 浓度>0.5 M 时，观察到吸附量非常少，因此毒性较小。ζ 电位研究表明，SNPs 在细胞表面的吸附与静电力的吸引力有关。还研究了吸附过程的平衡和动力学。吸附平衡等温线很好地符合朗缪尔模型。吸附动力学最符合拟一级动力学。这些发现为解释纳米颗粒与环境细菌的相互作用提供了基础。
