Conclusion
In the present study, we developed new antibody-conjugated magnetic NPs for the detection of HBsAg using an efficient conjugation strategy. The results demonstrated that the binding capacity of Fe3O4@SiO2/NH2 was comparable with commercially available products. Our designed method for conjugating anti-HBsAg antibody to a magnetic nanoparticle opens the way to produce a high capacity of magnetic NPs.
Methods
At the first step, Fe3O4 was modified with the silica and APTES (Fe3O4@SiO2/NH2) and chitosan (Fe3O4@CS) separately. The goat anti-HBsAg antibody was activated by two different protocols: Sodium periodate and EDC-NHS. Then the resulted composites were conjugated with activated goat anti-HBsAg IgG. An external magnet collected Bio-super magnetic NPs (BSMNPs) and the remained solution was analyzed by the Bradford method to check the amount of attached antibody to the surface of BSMNPs.
Results
The findings indicated that activation of antibodies by sodium periodate method 15-17 µg antibody immobilized on 1 mg of super magnetic nanoparticles (SMNPs). However, in the EDC-NHS method, 8-10 µg of antibody was conjugated with 1 mg of SMNPs. The resulting bio-magnetic NPs were applied for interaction with the HBsAg target using enzyme-linked immunosorbent assay (ELISA). About 1 µg antigen attached to 1 mg SMNPs, which demonstrated that the fabricated materials are applicable in the detection scope of HBsAg.