Development of a label-free immunosensor based on surface plasmon resonance technique for the detection of anti-Leishmania infantum antibodies in canine serum.

Abstract

In this work ,a surface Plasmon resonance (SPR) immune sensor was developed using an 11-mercaptoundecanoic acid (11-MUA) modified gold SPR sensor chip for the detection of anti- Leishmania infantum antibodies. The soluble antigens of L. infantum were securely immobilized on an SPR gold disk byan 11-MUA self-assembled monolayer. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM) techniques were employed in the characterization of the antigenim mobilization. After the immune sensor construction, canine serum positive for visceral leishmaniasis was added to its surface and showed significant variation in the SPR angle, indicating excellent sensitivity of the technique for antigen–antibody interaction detection. Moreover, the addition of negative serum was accompanied by as maller response, demonstrating that the immunosensor shows good specificity against anti-L. infantum antibodies. Therefore, this work demonstrates the success ful development of an SPR sensor for anti- L. infantum antibodies detection in short time, showing a great perspective as asensing system of visceral leishmania sisinende micregions.