Porous membranes having a polymeric coating and methods for their preparation and use

A method for decreasing biomolecule level needed to detect presence of the biomolecule in a biological sample comprising:

• a) providing a modified porous membrane having the structure of Formula (I), wherein Formula (I) is:
• wherein A is an e-beam reactive moiety, wherein poly (A)x is a polymer of the e-beam reactive moiety and x is a number of A monomers present in the poly (A)x polymer;
• wherein the linkage forms a bond between the poly (A)x polymer and a B group, and wherein the poly(A)x-linkage-B is a polymer coating covalently grafted to the porous membrane;
• b) incubating the modified porous membrane in the biological sample to determine if the biological sample comprises the biomolecule;
• c) washing the modified porous membrane to remove unbound material;
• and
• d) measuring biomolecule binding to the modified porous membrane and biomolecule binding to the unmodified porous membrane, wherein the biomolecule exhibits improved immobilization to the modified porous membrane, and thereby lowers the amount of biomolecule needed to detect the biomolecule in a biological sample.

A method of improving immobilization of a biomolecule on a porous membrane comprising:

• a) providing a modified porous membrane having the structure of Formula (I), wherein Formula (I) is:
• wherein A is an e-beam reactive moiety, wherein poly (A)x is a polymer of the e-beam reactive moiety and x is a number of A monomers present in the poly (A)x polymer;
• wherein the linkage forms a bond between the poly (A)x polymer and a B group, and wherein the poly(A)x-linkage-B is a polymer coating covalently grafted to the porous membrane;
• b) incubating the modified porous membrane in a sample comprising the biomolecule;
• c) washing the modified porous membrane to remove unbound material;
• d) measuring biomolecule binding to the modified porous membrane and biomolecule binding to the unmodified porous membrane;
• and
• e) comparing biomolecule binding to the modified porous membrane with biomolecule binding to the unmodified porous membrane, wherein immobilization of the biomolecule on the modified porous membrane is improved relative to immobilization of the biomolecule on the unmodified porous membrane.

A method for reducing detection time to determine presence of a biomolecule in a biological sample using an immunoassay comprising:

• a) providing a modified porous membrane having the structure of Formula (I), wherein Formula (I) is:
• wherein A is an e-beam reactive moiety, wherein poly (A)x is a polymer of the e-beam reactive moiety and x is a number of A monomers present in the poly (A)x polymer;
• wherein the linkage forms a bond between the poly (A)x polymer and a B group, and wherein the poly(A)x-linkage-B is a polymer coating covalently grafted to the porous membrane;
• b) incubating the modified porous membrane in the biological sample that may contain the biomolecule;
• c) washing the modified porous membrane to remove unbound material;
• d) measuring biomolecule binding to the modified porous membrane and biomolecule binding to the unmodified porous membrane;
• and
• e) comparing biomolecule binding to the modified porous membrane with biomolecule binding to the unmodified porous membrane at various time points, wherein the biomolecule binds more quickly to the modified porous membrane, thereby reducing the time needed to detect the presence of the biomolecule in the biological sample.