Rapid and Quantitative Determination of Biological Warfare Agent Brucella Abortus CSP-31 Using Surface Plasmon Resonance

A rapid and simple method for the real time monitoring of brucella abortuscsp-31 (b. abortus csp-31) by using surface plasmon resonance (spr) is first timereported. spr and electrochemical impedance spectroscopy (eis) were used tocharacterize the b. abortus csp-31 interaction on carboxymethyldextran modified golddisc with antibody. the eis data revealed a decrease in impedance after interaction ofantigen with antibody due to the effective binding. the present spr biosensor is able todetect 0.05 pm concentration of b. abortus csp-31 in phosphate buffered saline in lessthan 10 minute with linearity from 2.0 to 16.0 pm. the equilibrium constant (kd) andmaximum binding capacity of analyte (bmax) values for b. abortus csp-31 werecalculated to be 7.6 pm and 235.94 m?, respectively. this kd value classifies the antibodyas a high affinity one towards the antigen. moreover, thermodynamic parameter change ingibb’s free energy was calculated and found to be -63.34 kj/mol. interference study wasalso performed with b. abortus cell envelope (ce) antigen and a negative angle changewas observed with exemplifying specificity for the antigen-antibody interaction of b.abortus csp-31.