Signal Enhancement of Surface Plasmon Resonance Imaging for Detection of Acidovorax avenae subsp. citrulli

摘要

Signal enhancement based surface plasmon resonance (SPR) imaging was developed using gold nanoparticles (AuNP) for detection of Acidovorax avenae subsp. citrulli (Aac). The antibodies against Aac, monoclonal antibody 11E5 (MAb 11E5) and polyclonal antibody MPC (PAb MPC), were covalently immobilized on the 1:40 mixed self-assembled monolayer (SAM) surface for detection of Aac. The 10~7 cfu/ml of Aac was injected over the surface and was captured by immobilized antibodies on the sensing surface. PAb MPC conjugated to 10 nm of gold nanoparticles (PAb-AuNP) was flowed over the surface to enhance the SPR signal for detection of Aac. The MAb/Aac/PAb-AuNP assay provides a higher in signal enhancement than that of the PAb/Aac/PAb-AuNP assay. Moreover, the SPR signal using PAb-AuNP enhancement increases 23-fold in signal enhancement when compared with PAb enhancement. Thus, detection of Aac based SPR imaging can be used PAb-AuNP in signal enhancement for further improvement in the limit of detection (LOD).