Catalytic ferromagnetic gold nanoparticle immunoassay for the detection and differentiation of Mycobacterium tuberculosis and Mycobacterium bovis

A ferromagnetic gold nanoparticle based immune detection assay, exploiting the enhanced signal amplification of inorganic nanozymes, was developed and evaluated for its potential application in Mycobacterium tuberculosis complex (MTBC) organisms, simultaneous identification bovis. Ferromagnetic nanoparticles (Au–Fe3O4 NPs) were prepared their intrinsic peroxidase-like activity exploited to catalyse 3,3′,5’,5-tetramethylbenzidine (TMB) presence hydrogen peroxide (H2O2). When Au–Fe3O4 NPs functionalised by direct coupling with MTBC-selective antibodies, a assay (NPIDA) which could detect (MTB) differentiate M. In magnetic capability used sample preparation capture target bacterial cells. These incorporated into novel immunoassay species selective monoclonal antibodies (mAb) bound target. The formation blue TMB oxidation product, peak absorbance 370 nm, indicated successful limit NPIDA both MTB bovis determined be comparable conventional ELISA using same antibodies. Although limited matrix effects observed either offers reduced time confirmatory identification. This capable concentration, purification, immunological speciation. To our knowledge, it represents first immune-based diagnostic test identifying MTBC organisms simultaneously differentiating