A Study for Sensitivity Improvement of 3-D Lab-on-a-CD-Based Immunosensor

We have developed a three-dimensional (3D) Lab-on-a-CD immunosensor based on a competitive/noncompetitive assay for small endocrine disruptors and biomolecules. To improve the sensitivity of the 3D Lab-on-a-CD immunosensor, an immobilizing method of capturing-type antibody on the sensor surface was investigated. The method is based on the introduction of a highly reactive amino group to a P(MMA/CEMA) copolymer surface having chlorine, and utilizing a biotin-streptavidin system. The functionality of the 3D Lab-on-a-CD immunosensor was evaluated by measuring mouse IgG. The detection limit was found to be 3 f g/assay (3 x 10(-12) g/assay). After further modification, the 3D Lab-on-a-CD immunosensor, having some characteristics such as a substrate with highly integrated antibodies, is expected to be applicable for highly sensitive immunoassay.