Simultaneous coupled with Separate SELEX for heterocyclic biogenic amine-specific aptamers screening and their application in establishment of an effective aptasensor

Histamine (HIS) and tryptamine (TRY) are heterocyclic biogenic amines (BAs) often found in food products. The consumption of products containing high levels of BAs results in a wide range of life-threatening physiological reactions. The work described a Simultaneous coupled with Separate selection strategy for the screening of different aptamers against histamine and tryptamine. Aptamer HIS-3 and TRY-2 exhibited a good binding affinity ; specificity and pH stability to histamine and tryptamine were obtained with a dissociation constant of 11.62 ± 3.241 nM and 6.303 ± 1.758 nM, respectively. The preliminary binding mechanism was analyzed using a circular dichromatic (CD) and molecular docking. Finally, the identified aptamers were used for the development of a colorimetric method for the detection of histamine and tryptamine, achieving limits of detection of 1 ng/mL and 10 ng/mL, respectively. This aptamer-based method was further successfully employed to detect the BAs in fish and pork, providing a potential application for sensitive and efficient detecting multiple food risk factors.