The present invention provides among other things a silver nanoparticle-coated membrane that reduces biofouling. The membranes exhibit extended antimicrobial properties that prevents the buildup that causes biofouling, which in turn prolongs the life of the membranes. The membranes may be reverse osmosis membranes, microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, or any other membrane suitable for liquid processes.