Immunosensor Based on Antibody-Functionalized MoS2 for Rapid Detection of Avian Coronavirus on Cotton Thread

Infectious bronchitis virus (IBV), an avian coronavirus, significantly affects the performance of both the egg-laying and meat-type birds causing the foremost of economic loss in poultry industry. This paper aims to develop a rapid, low-cost, and sensitive biosensor for IBV detection by using molybdenum disulfide (MoS
₂
). MoS
₂
is a 2-D nanosheet which has strong high fluorescence-quenching ability when applied to a dye-labeled antibody (Ab). In this paper, we developed an Ab-functionalized MoS
₂
-based fluorescent immunosensor, which utilized the fluorescence resonance energy transfer (FRET) between the MoS
₂
and fluorescence dye during the Ab-antigen interaction. The assay was performed on a low-cost cotton thread-based microfluidic platform due to the good wicking property and flexibility. Upon the optimization of assay conditions, the immunosensor demonstrated remarkable sensitivity of 4.6 × 10
²
EID50 per mL and specificity with a dynamic linear response range of 10
²
-10
⁶
EID50 per mL for IBV standard solutions. The developed immunoassay successfully detected the IBV spiked chicken serum with satisfactory results. The foregoing presents its potential application for on-farm detection.