Quantum dots 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 another monoclonal
antibody was conjugated to QDs nanoparticles
as a detection system. Using these monoclonal
antibodies we recorded a good fluorescence
signal, the intensity of which 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 concentrations as low as 12.5 pg/μL in
less than 10 min. The reported technology
could be useful in the diagnostic investigation
of Mycobacterium tuberculosis and other
human pathogens in clinical specimens