Biofouling is still one of the most challenging issues of nanofiltration. One of the practical strategies to reduce biofouling is to develop novel anti-biofouling membranes. Herein, biogenic silver nanopartides (BioAg(0)-6) with the averaged diameter of only 6 nm were firstly grafted on the surface of polyamide NF membrane. The effect of grafted BioAg(0)-6 on the performance of thin-film composite (TFC) NF membranes was systematically investigated with a comparison to the grafted chemical AgNPs. BioAg(0)-6 grafted membrane (TFC-S-BioAg) increased the hydrophilicity of the TFC membrane and water permeability, while maintaining the relatively high salt rejection. The result of silver leaching experiment indicated that the grafted BioAg(0)-6 had a better stability on the membranes, the ratio of remained silver in the TFC-S-BioAg membrane was 95%, after soaked in pure water for 50 days. After 4 month immersion, the rejection of TFC-S-BioAg membrane remained more than 90% of initial rejection. The results of disk diffusion test revealed that both of TFC-S-BioAg membrane and TFC-S-ChemAg membrane showed effective anti-bacterial ability to inhibit Pseudomonas aeruginosa and Escherichia coli growth, the TFC-S-BioAg membrane showed more excellent and longer lasting antibacterial property. Therefore, BioAg(0)-6 grafted TFC membranes could be potential as an effective strategy to decrease biofouling in nanofiltration process. (C) 2015 Elsevier B.V. All rights reserved.