Supporting information Generation and properties of antibacterial coatings based on electrostatic attachment of silver nanoparticles to protein-coated polypropylene fibers Kiran K. Goli, 1 Nimish Gera, 2 Xiaomeng Liu, 3 Balaji M. Rao, 2 Orlando J. Rojas, 2,3,4 Jan Genzer 2,* 1 Department of Materials Science & Engineering North Carolina State University, Raleigh, NC 27695-7907, USA 2 Department of Chemical & Bimolecular Engineering North Carolina State University, Raleigh, NC 27695-7905, USA 3 Department of Forest Biomaterials North Carolina State University, Raleigh, NC 27695-8204, USA 4 Department of Forest Products Technology Aalto University, FI-00076 Aalto, Espoo, Finland. 1. Determination of the reduction of Ag + to Ag 0 The degree of conversion of silver ions to silver after reduction process was determined by using ion-selective electrode; perfectION™ comb Ag/S2 combination electrode (Mettler Toledo). The electrode selectively measures the free silver ions present in the prepared nanoparticle suspensions. A calibration curve was plotted by measuring the electron voltage potential (mV reading) of known concentration of standard silver nitrate standard solutions. The electron voltage potential of the silver nanoparticle suspension was then measured to determine the concentration of free silver ions present in the solution. The % conversions of silver ions after the preparation of silver nanoparticles are tabulated in Table S1. The data suggests that the reduction of silver ions during the synthesis of nanoparticles has increased as the concentration of silver nitrate is increased from 0.25 to 2 mM. * Corresponding author: jan_genzer@ncsu.edu, +1-919-515-2069