Application of a thermally-reversible polymer-antibody conjugate in a novel membrane-based immunoassay

We have developed a novel method to immobilize antibodies onto a cellulose acetate membrane using a conjugate of an N-isopropylacrylamide polymer covalently bound to the antibody. When compared with the unconjugated antibody, over 30-fold increase in retention of the antibody on the membrane was observed when it was conjugated to poly (N-isopropylacrylamide). Studies of the polymer-membrane interaction suggest a combination of hydrophobic and ionic forces, especially the former, is responsible for the high retention. We applied this novel immobilization technology in the development of a membrane-based immunoassay.