A dual-donor FRET based aptamer sensor for simultaneous determination of histamine and tyramine in fishes

The presence of biogenic amines (BAs) in food is not only important from a toxicological view, but can also be used as an indicator of food spoilage. However, the design of biosensors for the detection of BAs is very limited. Hence, in this work, a dual-donor fluorescence resonance energy transfer (FRET) aptasensor was established for simultaneous determination of histamine (HIS) and tyramine (TYR) using dual-color quantum dots (QDs) as energy donors and two-dimensional molybdenum sulfide nanosheets (MoS 2 NSs) as energy acceptor. Specific aptamer for HIS (Apt 1) and TYR (Apt 2) were labeled with two fluorescence emission QDs (QD 530 and QD 625 ), respectively. On the basis of the excellent adsorption ability of MoS 2 NSs toward aptamer, the fluorescence quenching can be observed between MoS 2 NSs and QD 530 -Apt1 and QD 625 -Apt2. Upon the addition of HIS and TYR, the aptamer conformation switches induced by the target binding mitigate the interaction force of MoS 2 NSs and QD 530 -Apt1 and QD 625 -Apt2, resulting in the fluorescence recovery. The method displays good sensitivity with limit of detection (LOD) of 0.1 ng/mL for HIS and 0.25 ng/mL for TYR, respectively. It can also be applied to the HIS and TYR detection in spiked fish samples with recovery of 95.2%∼106.6%, demonstrating its prospect in the sensitive detection of BAs in animal-derived foodstuff.