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) immunosensor 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 by an 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 antigen immobilization. After the immunosensor 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 a smaller response, demonstrating that the immunosensor shows good specificity against anti-L. infantum antibodies. Therefore, this work demonstrates the successful development of an SPR sensor for anti-L. infantum antibodies detection in short time, showing a great perspective as a sensing system of visceral leishmaniasis in endemic regions.

Label‐Free and Regenerative Electrochemical Microfluidic Biosensors for Continual Monitoring of Cell Secretomes

“…Therefore, the incubation times for SAM (Figure S2a, Supporting Information), SPV (Figure S2b, Supporting Information), biotinylated anti‐albumin coatings (Figure S2c, Supporting Information), and the media blocking steps (Figure S2d, Supporting Information) were determined to be 1 h. Subsequently, the sensing performance of optimized EC biosensors was evaluated inside a complex sample solution. However, the use of complex media having high concentrations of nonspecific binding proteins that are 10 5 times higher than those of the analytes of interest in the media, may alter the measurements and lead to incorrect results 30. To assess the applicability of our biosensor toward real samples, we carried out measurements using cell culture media, which usually included high concentrations of fetal bovine serum (FBS) containing around ≈99 mg mL −1 bovine serum albumin and other molecules but not the target antibody, that is, human serum albumin.…”

Recent Advances in Scanning Electrochemical Microscopy for Biological Applications

“…Through this successful use of SECM in detecting the interaction between NSE and biotinylated antibody, the authors proposed a new application of SECM to fabricate miniaturized antibody-based analytical testing platforms. Instead of detecting antigens, Damos et al [137] recently developed an immunosensor to detect an anti- Leishmania infantum antibody using SECM. First, an 11-mercaptoundecanoic acid self-assembled monolayer was constructed on a bare gold electrode, followed by the immobilization of soluble L. infantum antigens in the SPR system.…”

SPR analysis of the interaction between a recombinant protein of unknown function in Leishmania infantum immobilised on dendrimers and antibodies of the visceral leishmaniasis: A potential use in immunodiagnosis

“…Therefore, these hypothetical protein genes are interesting targets for research. Additionally, there is also an incentive to develop immunosensors using new transducers to improve the sensitivity and reproducibility of these assays (Souto et al, 2013).…”