Half-antibody spur one-to-one recognition mechanism can function with chemical-staining technology for next-generation lateral flow immunoassay

Nanomaterials-based lateral flow immunoassays (LFIAs) have gained great commercial success in small molecule monitoring, while a bigger picture of this technique can be torn up by sensitivity issues, resulting from the difficulties in potentiating bio functionality of nanoprobes laden with antibodies (Abs). Herein, a novel one-to-one recognition marker, colored half-Ab (cHAb) by a facile “chemical-staining technique”, was engineered into LFIAs vehicle to leverage its high luminance capability and Fab independent binding behavior of HAb. The designed cHAb not only simplified the preparation process of probes using dyes, but also effectively improved the unique recognition ability of the target via HAb, thereby abandoning the inherent limitations of traditional nanomaterials and Abs, and imparting a high sensitivity. Proof-of-concept was proved by introducing coomassie bright blue R-250 (CBBR) stained HAb as examples to detect clenbuterol (CLE). The superior detection advantage of HAb was first verified by indirect competitive ELISA (ic-ELISA), demonstrating that HAb can improve the sensitivity by about 3.5 folds compared with Ab. In addition, a cHAb-based LFIA (HAb-CLFIA) was developed, proving that applying HAb can improve the detection sensitivity of about 1.8-folds whilst still exhibiting a wide linear range coverage of 80 % of the cut-off value. Spiked honey sample testing can detect CLE at least 10 μg kg −1 , providing the same sensitivity to water samples, validating that HAb-CLFIA is equipped with good applicability. Importantly, HAb combined with chemical-staining technology exhibits great potential for next-generation LFIA for small molecule contaminants detection.