Effective pathogen removal in sustainable natural fiber *Moringa* filters

Pathogen contamination of water has a massive impact on global human health. Viruses are particularly challenging due to their small size and ability to exist as free virions or adsorbed to larger particles, making them difficult to remove with low-energy media filtration. Consequently, higher energy or chemical processes such as chemical disinfection, UV irradiation, and membrane filtration are often required. This work presents sustainable fiber filters fabricated from minimally processed natural materials (cotton, silk, flax) functionalized with a simple aqueous extract containing cationic proteins from Moringa oleifera seeds. These MO-functionalized fiber filters achieved >7 log10 (99.99999%) removal of both MS2 bacteriophage (virus surrogate) and Escherichia coli, offering a comprehensive low-cost, low-energy, and low environmental impact solution for pathogen removal from water.