Silver nanoparticle-coated silica hybrid particles as antibiofouling agent on filter materials

Pathogenic microorganisms filtered on the medium can proliferate and be a source of contamination when an appropriate nutritional condition is attained by the filtered dust materials (i.e., biofouling). Silica microparticles with coated AgNPs can be a promising antibiofouling agent for filter-materials because the microparticles are well dispersible without ligands and easily collectable by a conventional centrifugation and furthermore, the nanoparticles coated on the microparticle can exhibit nano-properties. Here we introduce silver nanoparticle-coated silica (AgNPs@SiO₂) hybrid particles synthesized by seed-mediated growth method and their applications as a biocidal coating material for air and water filtration systems. The AgNPs@Si02-immobilized filter-materials for both air and water exhibit excellent antibacterial activity toward gram-negative bacteria, Escherichia coli, and gram-positive bacteria, Staphylococcus epidermidis and Pseudomonas aeruginosa.