A biomimetic sensor surface to detect anti-β2-glycoprotein-I antibodies as a marker for antiphospholipid syndrome

A biomimetic sensor has been developed, that allows for quantification of autoantibodies related to the antiphospholipid syndrome (APS). Autoantibodies directed against the β(2)-glycoprotein-I (β(2)GP-I) are known as the best markers for diagnosis of APS, however, detection of such antibodies is still a challenge. The epitopes of β(2)GP-I are exposed upon binding to negatively charged membranes. The surface of the sensor chips was therefore modified with such type of membranes, on which β(2)GP-I molecules were subsequently immobilized as recognition elements. Using the label-free method, reflectometric interference spectroscopy, it was possible to quantify anti-β(2)GP-I antibodies and to calibrate the sensor chip in buffer. A mild regeneration procedure allows for many consecutive measurements without stripping off the membrane in between.