Quantum dot nanoparticle-based lateral flow assay for rapid detection of Mycobacterium species using anti-FprA antibodies.

A lateral flow (LF) device combined with Quantum dots (QDs) technology was developed for rapid detection of a specific mycobacterial flavoprotein reductase (FprA). In order to develop the LF assay based on a double-antibody sandwich format, two monoclonal antibodies recognizing different epitopes located in separated FprA domains, were identified. The first monoclonal antibody was immobilized onto the detection zone of a porous nitrocellulose membrane, whereas an other monoclonal antibody was conjugated to QDs nanoparticles as a detection system. Using these monoclonal antibodies we recorded a good fluorescence signal, whose intensity was directly proportional to the concentration of FprA protein. The use of antibodies conjugated with fluorescent semiconductor QDs via biotin-streptavidin bridge, allowed the detection of FprA protein at concentration as low as 12.5 pg/?l in less than 10 min. The reported technology could be useful for the diagnostic investigation of Mycobacterium tuberculosis and other human pathogens in clinical specimens.