A “on-off-on” fluorescence aptasensor using carbon quantum dots and graphene oxide for ultrasensitive detection of the major shellfish allergen Arginine kinase

•A developed FRET-based aptasensor for detection of shellfish Arginine kinase (AK).•Good sensitivity, reproducible and user-friendly operation has been obtained.•Rapid and accurate shellfish sample detection with simple pre-processing. Shellfish allergy is a crucial public health problem and a severe food safety issue, resulting in an urgent need for an accurate, simple and sensitive method to detect the shellfish allergens in complex food systems. Herein, we have desighed an “on-off-on” fluorescence aptasensor based on fluorescence resonance energy transfer (FRET) using prepared carboxyl groups functionalized CQDs (cCQDs) and graphene oxide (GO) for the detection and quantification of the major shellfish allergen arginine kinase (AK). The FRET aptasensor allowed for the sensitive detection of AK in the range of 0.001–10 μg/mL with the limit of detection (LOD) of 0.14 ng/mL (S/N = 3), and the limit of quantitation (LOQ) of 0.27 ng/mL (S/N = 10). This reliable, accurate and specific aptasensor with user-friendly operation may provide new perspectives in the application of fluorescence technologies for food allergens detection in the field of food safety.