An article is provided. The article comprises a nonwoven substrate having a copolymer grafted thereto, and a dried coating adhered to the substrate. The copolymer comprises interpolymerized monomer units of a quaternary ammonium-containing ligand monomer, an amide monomer, and an oxy monomer. The coating comprises a plurality of test microorganisms. Optionally, the coating further comprises a water-soluble or water-dispersible polymeric binding agent. A process challenge device comprising a body having a hollow channel with said article fixed disposed therein is also provided. Methods of using the article or the process challenge device for determining the efficacy of a disinfection process are also provided.