Screening and identification of an aptamer as novel recognition molecule in the test strip and its application for visual detection of ethyl carbamate in liquor

There is still a great challenge of on-site and rapid detection for ethyl carbamate (EC) in liquor. Herein, the aptamer (EC1) against EC was firstly screened by Capture-SELEX strategy, and its affinity and binding sites for EC were further investigated by fluorescence assay and molecular docking . Under the premise of retaining the structural features, the obtained aptamer was further truncated into a short sequence (named EC1-34), which has the dissociation constant of 17.97 ± 0.98 nM for EC. Subsequently, a visible, rapid, and cost-effective test strip was firstly designed for EC detection in liquor, in which the cationic polymer was used to efficiently capture the recognition probe conjugated with EC1-34 aptamer and gold nanoparticles (AuNPs). The minimum detection limit of the test strip is calculated as 2.14 μg⋅L -1 . The rapid test strip can be widely used for EC detection in liquor due to the advantages of high stability, convenience and selectivity .