Establishment of evanescent wave fiber-optic immunosensor method for detection bluetongue virus

The evanescent wave fiber immunosensors (EWFI) technique was developed for the real-time rapidly sensitive and specific detection of the monoclonal antibody 3E2 of BTV. The outer-core protein VP7 of BTV was labled on the surface of the exposed fiber-optic core. The monoclonal antibody 3E2 of BTV VP7 were added and then the goat ant-rat IgG conjugated with Cy3 was captured. After the 532nm pulse (excitation source) reached the fiber probe, evanescent wave was generated, which excited the Cy3 bound to the immuno-complex and produced the fluorescent signal, which was changed into electrical signals read through computer. The preliminary results suggested that a detection limit of 10ng/ml was measured for the monoclonal antibody 3E2, which is equal to the sensitivity of ELISA. The 3E2 sample was specifically detected through the EWFI assay in 15min, and the fiber can be recycled at least ten times through TEA solution condition. This developed EWFI was a real-time rapidly sensitive and specific way for the detection of BTV antibodies.