Edwardsiella tarda has been recognized as one of the most serious aquatic animal pathogens. Real-time and accurate means of detection is the key for prevention and control of spread of Edwardsiella tarda. In this present work

a novel detection strategy is designed to realize rapid and specific determination of Edwardsiella tarda by labeling Edwardsiella tarda monoclonal antibody（ Ab） with QDs. The results show that the fluorescence of these QDs-Ab bioconjugates is quenched by GO to produce a bacterium capture probe. And the optimal quenched concentration of Graphene oxide is 60 μg/L. When the bacterium capture probe is exposed to the targets of Edwardsiella tarda

orange color fluorescence is turned on by releasing the QDs-Ab due to the antibody antigen combination. The specificity of the FRET sensor towards Edwardsiella tarda is examined by comparing with controls such as Vibrio splendidus

Vibrio alginolyticus

Vibrio parahaemolyticus and Aeromonas hydrophila with the same condition. The control group can not cause obvious fluorescence alteration

while the experimental group results in significant fluorescence enhancement. Therefore

the sensor has good potential to expand its application to the early diagnosis determination of bacterium.