Signal enhancement based surface plasmon resonance imaging (SPR imaging) was developed using gold nanoparticle (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 of mixed self-assembled monolayer (mixed SAMs) surface for detection of Aac. The 107 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 nanoparticle (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 PAb/Aac/PAb-AuNP assay. Moreover, SPR signal using PAb-AuNP enhancement increases 23 – fold in signal enhancement when comparing to PAb enhancement. Thus, the detection of Aac based SPR imaging can be used PAb-AuNP in signal enhancement for further improvement in limit of detection (LOD).