Label-free fluorescence lateral flow biosensing platform based on host-guest recognition for on-site detection of amantadine in egg samples.

Rapid, accurate and convenient detection of illegally added drugs are of critical importance in food safety. Herein, based on the host-guest recognition strategy, we establish a novel label-free fluorescence lateral flow assay (LF-LFA) platform for detection of amantadine (AMD) in egg samples. Specially, two fluorescence reporters-BSA-β-CD@BER (formed via host-guest interaction) and BER-BSA (generated through AIE effect), are effectively designed. This platform can enable "turn-on" FL detection through host-guest interaction between cucurbit[7]uril (CB[7]) and AMD, as well as between CB[7] and BSA-β-CD@BER, without the need for fluorescent labeling of target molecule (AMD). As a result, it has successfully achieved sensitive detection of AMD with a low limit of detection (LOD = 2.1 ng mL-1), wide linear detection range (2.5-100 ng mL-1), high specificity (CR ≤ 4%) and fast response (only 8 min). It will be expected to provide a novel avenue for rapid on-site detection of more illegal drugs in practices.