DETERMINATION OF SUBGROUP J AVIAN LEUKOSIS VIRUS BY SURFACE PLASMON RESONANCE IMMUNOSENSOR

Two novel Fourier transform-surface plasmon resonance immunosensors were fabricated for the determination of the subgroup J avian leukosis virus. The immunosensors were based on a functionalized gold substrate and immobilized gold-silver nanoparticles. For the first immunosensor, the gold substrate was functionalized with a dense self-assembled monolayer of 3-mercaptopropionic acid through gold-sulfur bonds, and then protein A which can combine subgroup J avian leucosis virus antibody on the antigen nonbinding site was modified on the sensor chip surface via covalent bonds formed between the amino groups and the activated carboxyl groups of 3-mercaptopropionic acid. After inactivation by ethanolamine, the sensor chip immobilized the antibody by the combination with protein A to produce a sensor. For the second immunosensor, 1,6- hexanedithiol formed a self-assembled monolayer on the sensor chip surface through gold-sulfur bonds. Then gold-silver nanoparticles were immobilized on the sensor chip by gold-sulfur and silver-sulfur bonds. The modification by various reagents and determination of the subgroup J avian leukosis virus antigen were the same as in the first immunosensor. The immunosensors determined the subgroup J avian leukosis virus antigen to analyte concentrations of 659 TCID50 center dot mL(-1) and 1054 TCID50 center dot mL(-1), respectively. The result suggested that introducing gold-silver nanoparticles to the Fourier transform-surface plasmon resonance immunosensor is beneficial to effectively improving the sensitivity of the immunosensor. Moreover, the contrast experiment presented that the immunosensors showed high specificity for the subgroup J avian leucosis virus detection.