Development of Nano-ELISA Method for Serological Diagnosis of Toxoplasmosis in Mice

Toxoplasmosis is a widespread parasitic disease caused by a protozoan parasite Toxoplasma gondii. Currently, nanotechnology has been used for the diagnosis of many infectious diseases. It could be due to the fact that nanoparticles play an important role in accurate and fast diagnosis. The purpose of this study was to design a Nano-enzyme linked immunosorbent assay (Nano-ELISA) kit using excreted/secreted (E/S) antigens to have higher sensitivity and specificity than those reported for the designed enzyme-linked immunosorbent assay (ELISA) kit for the diagnosis of Toxoplasmosis in mice. Firstly, the serum samples were collected from 15 infected mice with T. gondii and 15 healthy ones. Then, E/S antigens were separated from parasite tachyzoites and used for designing an ELISA kit. In addition, the mice sera were evaluated using the designed ELISA kit. Finally, the serum samples were assessed by Nano-ELISA kits designed with E/S antigen and conjugate of gold nanoparticles. The obtained results of the present study showed that the sensitivity and specificity of the designed ELISA kit were reported as 80% and 86.66%, respectively, that both improved to 93.33% in these sera with the designed Nano-ELISA kit. This finding revealed the significant improvement of sensitivity and specificity using gold nanoparticles in designing the ELISA kit. Furthermore, according to the literature, the use of E/S antigens in designing recognizable ELISA kits has been always highlighted considering the presence of numerous antigens in T. gondii. The results of this study revealed that the use of E/S antigens in the preparation of an ELISA kit was very effective. This is very important, especially in the lower titers of antibody requiring a more accurate diagnosis. On the other hand, the Nano-ELISA method designed with E/S antigens can be more sensitive and specific than ELISA for the diagnosis of Toxoplasmosis and can be the basis for further studies in this regard.