Abstract

A label-free optical immunosensor was developed based on surface plasmon resonance (SPR) method for rapid and selective detection of Brucella melitensis. This immunosensor was constructed by immobilizing capture antibody on 11-mercaptoundecanoic acid modified gold disk. This fabricated immunosensor detected B. melitensis at a concentration range from 10(3) to 10(7) cell mL(-1) (R-2 = 0.998) and a detection limit of 100 cell mL(-1). Additionally, the kinetic equilibrium dissociation constant (KD) for assessment of the interaction affinity was calculated as 1.1 x 10(-9) mol L-1 that can be considered as high affinity interaction. This SPR immunosensor provided advantages in term of fast response, label free and accurate detection of B. melitensis in analytical systems.