Tulobuterol

Beta-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-IR (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 assays flexibility, utility, and accuracy, performing well as a point-of-care testing platform for various application scenarios.

Excellent pretreatments before instrumental analysis are critical for separation and determination of target compounds for discovery of new drugs from herb medicines. We developed a rapid and highly-selective method to separate the bioactive compounds from herbal extract using protein affinity-selection spin column, which was packed with the new sorbent materials from integrating the recombinant β₂-adrenoceptor (β₂-AR) directly out of cell lysates onto the surface of microspheres. Protein affinity-selection spin column was placed in a centrifugal tube, where after the non-specific binders were released to the filtrate under the operational centrifugation, the specific binders on the spin column were cleaned with a washing solvent for LC-MS analysis. The known agonists of β₂-AR were retained/released on protein affinity-selection spin column but not on control column, demonstrating the method with good recovery (79.4∼95.7 %) and high repeatability (RSD < 3.5 %). The adsorption features of three ligands on the spin column were described best by Prism saturation binding model, and the high-affinity binding and the large binding capacity of the spin column make it feasible to trap the trace analytes effectively. It was applied in separating bioactive compounds from Alstoniae Scholaris extract, two of which were identified as picrinine and oleanolic acid in combination with LC-MS and verified as the potential agonists towards β₂-AR though molecular docking and cell experiments. Our study demonstrated that, the spin column with the immobilized protein sorbents in the centrifugal filter device represents a promising tool, enabling rapid and target-specific affinity separation of the bioactive compounds from herbal extract.