Amplification of SPR responses for the immunoreaction using anti HIV gp41 antibody by the method of molecular accumulation

Abstract

Improvement of the detection limit of surface plasmon resonance (SPR) apparatus is an important issue when it is applied to immunosensor to detect the biological substances in serum and/or urine. In this study, we investigated two kinds of molecular accumulation methods. The method of consecutive accumulation, in which the second and third antibodies were successively bound onto the antigen (gp41 of human immunodeficiency virus-1), enhanced the SPR response to the anti gp41 antibody binding by about 7 fold. On the other hand, the method of complexed antibody accumulation, in which the second and third antibodies were simultaneously bound onto the antigen, gave the higher response by over 10 fold. In these methods, the appropriate second and third antibodies must be chosen in addition to determination of the preferable concentration.