The sensitivity, specificity, positive predictive value, and negative predictive value showed an appropriate performance of the LSPR-based method (85%, 100%, 100%, and 86%, respectively). Furthermore, 40 sera from true negative samples and positive patients were used to evaluate the performance of this method by comparing its outcomes with the gold standard (culture), standard tube agglutination test, and anti-brucellosis IgM and IgG levels (ELISA). The detection of captured anti-Brucella antibody was performed by measuring the redshift on LSPR peak followed by the determination of cutoff value, which indicated a significant difference between controls and true positive patients ( P value < 0.01). After some optimizing processes, dynamic light scattering was used to characterize the probe.
For this purpose, smooth lipopolysaccharides were extracted from Brucella melitensis and Brucella abortus and fixed on the surface of the gold nanoparticles through covalent interactions. This research aimed to design and evaluate the performance of a novel technique based on the localized surface plasmon resonance (LSPR) to eliminate or reduce existing shortcomings. Although the laboratory findings are the most reliable diagnosis today, the current laboratory methods have many limitations.
Brucellosis is considered as the most common bacterial zoonosis in the world.