Development and evaluation of a SPR-based immunosensor for the diagnosis of Cutaneous Leishmaniasis

C. Y. CHAIN; D. E. PIRES SOUTO; M. A. DAZA MILLONE; L. T. KUBOTA; H. MONTEIRO DE ANDRADE; M. E. VELA

Riva del Garda

Conferencia; 5th International Conference on Bio- sensing technology; 2017

Protozoan Leishmania is the etiological agent of Cutaneous Leishmaniasis disease, which needs urgent progress in its immunological diagnosis. Surface Plasmon Resonance (SPR) is a promising technique for the development of immunosensors with biomedical applications. In this work, a SPR-based immunosensor has been developedby the first time for real time and label free immunoassay for detection of anti-Leishmania antibodies in serum samples. Leishmania antigens (soluble extract and specific recombinant protein) was successfully immobilized on a SPR sensor chip via activated mixed self-assembled monolayer (SAM) by amide coupling. After the sensor construction, a pool of canine sera infected with Leishmania was added to its surface and the antibodies were detected in appropriate sera dilutions, indicatingexcellent sensitivity of the technique for detection of antigen?antibody interaction. The addition of a pool of negative canine serum at low dilutions to the sensor surface was accompanied by a null or very low response. Then, the operational parameters of the immunoassay were optimized and defined: time of immobilization and antigen concentration, serum dilution, preventing of nonspecific bindings with solution of BSA and surface regeneration method.