Nanostructured spore carrier
View Patent ↗Spore carriers suitable for use in biological indicators are described. The spore carriers include a substrate such as polymeric film or non-woven web with a hydrophilic nanostructured layer bonded to it. Spores are bonded to the nanostructured layer. Nanostructured layers including nanoparticles, such as acid-sintered silica nanoparticles are described. Biological indicators including such spore carriers are also described.
1. A spore carrier comprising a substrate, a hydrophilic nanostructured layer bonded to a surface of the substrate; and spores bonded to the nanostructured layer; wherein the nanostructured layer comprises silica nanoparticles.
2. The spore carrier of claim 1 , wherein the nanostructured layer has a receding contact angle of no greater than 50 degrees as measured by the Contact Angle Method.
3. The spore carrier of claim 1 , wherein the nanostructured layer has a receding contact angle of no greater than 20 degrees as measured by the Contact Angle Method.
4. The spore carrier of claim 1 , wherein the silica nanoparticles are acid sintered.
5. The spore carrier of claim 1 , wherein the nanoparticles have an average diameter of no greater than 20 nm.
6. The spore carrier of claim 1 , wherein the nanostructured layer has an RMS roughness of at least 10 nm.
7. The spore carrier of claim 6 , the nanostructured layer has an RMS roughness of no greater than 500 nm.
8. The spore carrier of claim 1 , wherein the nanostructured layer further comprises microparticles.
9. The spore carrier of claim 1 , wherein the nanostructured layer further comprises a binder.
10. The spore carrier of claim 9 , wherein the binder comprises a tetraalkoxysilane.
11. The spore carrier of claim 1 , wherein the substrate is a polymeric substrate.
12. The spore carrier of claim 11 , wherein the polymeric substrate comprises polyester.
13. The spore carrier of claim 12 , wherein the polymeric substrate comprises polypropylene.
14. The spore carrier of claim 1 , wherein the substrate is a woven or non-woven web.
15. The spore carrier of claim 1 , wherein the substrate is a film.
16. The spore carrier of claim 1 , wherein the spores comprise at least one of Geobacillus stearothermophilus and Bacillus atrophaeus.
17. A biological indicator comprising a housing and the spore carrier of claim 1 .
18. The spore carrier of claim 1 , wherein the wherein the nanostructured layer comprises silica nanoparticles deposited out of an aqueous coating composition having a pH of less than 3.