A target-triggered domino platform for multimode-guided lateral flow immunoassay of multiple β-agonists

Abstract

β-agonists are seriously threatening the human health because of their illegal used in foods. In this work, a lateral flow immunoassays (LFIA) were developed for multimode determination of residues of ten β-agonists in real samples. Here, the developed platform used Ms-Pd/Pt-pAbNPs nanoprobes, fabricated by decorating the surface of Mulberry-shaped Palladium/Platinum nanoparticels (Ms-Pd/PtNPs) with self-prepared broad-spectrum polyclonal antibody (pAb). Through a competitive strategy, salbutamol as the analyte, a visual sensing mode was realized by the Ms-Pd/Pt-pAbNPs being trapped on the surface of test line (T line), offering a limit of detection (LOD) of 1.0 ng/mL with naked eye. Subsequently, Ms-Pd/Pt-pAbNPs with oxidase-like performance catalyzes the TMB into oxTMB with blue color, achieving a detection range from 0.01 to 100 ng/mL based on the colorimetric sensing LFIA, with an LOD as low as 0.01 ng/mL and 75-fold lower than that of traditional immunoassay (ELISA). Then, the oxTMB converts near-infrared (NIR) laser into energy, causing a photothermal-based LFIA for detection of salbutamol range from 0.01 to 100 ng/mL with an LOD as low as 0.01 ng/mL as well as 75-fold lower than of ELISA. The target triggered reactions like “a domino platform” was constructed for detection of a series of targets in multimodal-based LFIA, contributing to the as-prepared pAb with broad comibation capability. Meanwhile, the developed multimodal LFIA enabled to detect salbutamol in pork, beef, and animal feed samples with satisfactory recovery. Consequently, the integrated output signals in this multimodal LFIA enhanced the assay’s flexibility, utility, and accuracy, performing well as a point-of-care testing platform for various application scenarios.