Ethylene oxide sterilization sensor including acid-functional sorbent and method of use

1. An ethylene oxide sterilization sensor comprising:

a heat-shrinkable film;

an acid-functional porous sorbent in thermal contact with the heat-shrinkable film; and

an acid having a boiling point above 120° C. and a pKa of no greater than 2.5, wherein the acid is impregnated in or covalently attached to the porous sorbent.

2. The sterilization sensor of claim 1 wherein the heat-shrinkable film comprises a physically and/or chemically crosslinked polymer.

3. The sterilization sensor of claim 2 wherein the heat-shrinkable film comprises a thermoplastic polyurethane elastomer, a polyurethane with polystyrene and poly(1,4-butadiene) blocks, an ABA tri-block copolymer of poly(tetrahydrofuran) and poly(2-methyl-2-oxazoline), a polyhedral oligomeric silsesquioxane-modified polynorbornene, a polyethylene/Nylon-6 graft copolymer, a polyethylene, a copolymer of ethylene and vinyl acetate, a polyurethane, a polynorbornene, a polyether, a polyacrylate, a polyamide, a polysiloxane, a polyether amide, a polyether ester, a trans-polyisoprene, a polymethyl methacrylate, a polyoctylene, a polycyclooctenes, an inorganic-organic hybrid polymer, a copolymer blend of polyethylene and a styrene-butadiene copolymer, a urethane-butadiene copolymer, a polymethyl methacrylate, a polycaprolactone, an oligocaprolactone copolymer, and combinations thereof.

4. The sterilization sensor of claim 1 wherein the acid-functional porous sorbent comprises activated carbon, porous silica, zeolites, porous organic polymer, or combinations thereof.

5. The sterilization sensor of claim 1 wherein the acid comprises acid moieties covalently attached to the porous sorbent.

6. The sterilization sensor of claim 5 wherein the acid comprises covalently attached acid moieties selected from sulfonic acid (—SO 3 H) groups and phosphonic acid (—PO 3 H 2 ) groups.

7. The sterilization sensor of claim 5 wherein the acid is present in an amount of 0.2 mmole to 5.5 mmole of acid moieties per gram of acid-functional porous sorbent.

8. The sterilization sensor of claim 1 wherein the acid comprises acid compounds impregnated within the porous sorbent.

9. The sterilization sensor of claim 8 wherein the acid is selected from acid compounds comprising sulfuric acid, phosphoric acid, methanesulfonic acid, methanephosphonic acid, benzene sulfonic acid, toluene sulfonic acid, or a combination thereof.

10. The sterilization sensor of claim 8 wherein the acid is present in an amount of 5 wt-% to 80 wt-%, based on the total weight of the acid-functional porous sorbent.

11. The sterilization sensor of claim 1 wherein the acid-functional porous sorbent is adhered to the heat-shrinkable film.

12. An array comprising a plurality of the ethylene oxide sterilization sensors of claim 1 .