Influenza is a common acute viral disease that has caused massive harm to human, so a rapid pathogen-detecting method is required for monitoring the status of the disease. Quantum dots are promising emerging fluorescent probe for diagnostic assay. In this work, water soluble ZnO quantum dots were covalently conjugated to rabbit anti-chicken IgY antibody to prepare the quantum dots-linked secondary antibody. The conjugate was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorescence spectrophotometer. Fluorescent quantum dots-based immunosorbent assay was conducted to determine the concentration of influenza B virus. We found that rabbit anti-chicken IgY antibody augmented its molecular weight while coupled to ZnO quantum dots, but the emission spectrum didn’t change. More importantly, the luminescence intensity of QDs correlated to viral concentration in a linear relationship. These results may suggest a potential new approach for quantifying virus, pathogenic bacteria and toxic molecule.