Abstract: Materials and methods for the selective removal of lipopolysaccharide during the purification of molecules of bio-pharmaceutical interest are based on a polymeric substrate that binds lipopolysaccharide. Preferably, the polymeric substrate is selective for at least one of heptose and 2-keto-3-deoxyoctonic acid. The substrate can be formed by a process comprising: (i) contacting a homogeneous polymer solution and a template solution; (ii) carrying out a phase inversion of the resulting solution; and (iii) removing the template.