Fluorescent Immunosorbent Assay for Chikungunya Virus Detection

<b><i>Background:</i></b> When infected with the chikungunya virus (CHIKV), 3% to 28% of CHIKV-infected individuals remain asymptomatic, necessitating the development of improved high-throughput screening methods to overcome the limitations of molecular diagnostics or enzyme-linked immunosorbent assays (ELISAs). <b><i>Objective:</i></b> In this study, two novel monoclonal antibodies (mAbs) targeting envelope 1 (E1) of CHIKV were developed and applied in a fluorescence-linked immunosorbent assay (FLISA) using coumarin-derived dendrimer as the fluorophore. <b><i>Methods:</i></b> The performance of the FLISA was compared with that of ELISA. <b><i>Results:</i></b> Using the two novel mAbs (2B5 and 2C8), FLISA could detect 1 × 10⁵ PFU/mL of CHIKV, exhibiting a 2-fold lower limit of detection (LOD) compared to ELISA. The LOD of FICT corresponded to a comparative threshold value of 23.95 and 4 × 10⁶ of RNA copy number/µL. In the presence of human sera and blood, virus detection by FLISA was 3-fold better than ELISA, with an LOD of 2 × 10⁵ PFU/mL. Sera and blood interfered with the ELISA, resulting in 6 × 10⁵ PFU/mL as the LOD. <b><i>Conclusions:</i></b> FLISA using two novel mAbs and coumarin-derived dendrimer is a superior diagnostic assay for detecting CHIKV in human sera and blood, compared to conventional ELISA.