posted on 2024-03-15, 22:29authored byArmando
H. Becerra, Mariana G. Flores, José P. Palma-Nicolas, Gonzalo Ramírez-García, Luz M. López-Marín
Considering that more than 10 million people develop
tuberculosis
disease (TB) each year and that nearly 3 million of them are never
diagnosed, label-free screening methods constitute one of the top
public health priorities worldwide. Herein we report the fabrication
of a plasmonic system for the detection of TB-associated antibodies.
Gold nanoparticles (AuNPs) were synthesized at controlled sizes and
modified to display antigen lipid glycans from mycobacteria, the group
of organisms comprising the TB causal agent. Facile self-assembly
procedures were employed to form mycobacterial phosphatidylinositol
mannoside (PIM)-containing unilamellar liposomes (mycosomes) and to
attach them onto gold surfaces using thiol chemistry. Using enzyme-linked
immunoassays with rabbit hyperimmune sera, the constructs were found
to specifically capture antilipid antibodies, presenting a dose-dependent
response. Also, the functional hybrid nanoparticles showed localized
surface plasmon resonance (LSPR) shifts of up to 2 nm upon their interaction
with specific antibodies, indicating their suitability for the optical
transduction of antigen–antibody reactions. Finally, the applicability
of the system for real-world detection of TB-associated antibodies
was demonstrated through analysis of 12 samples of human individuals,
including 7 cases with pulmonary TB. To the best of our knowledge,
this is the first biomimetic nanogold–lipid system for the
implementation of lipids as immunosensing reagents for the plasmonic
detection and diagnosis of TB.