Smartphone-assisted portable amperometric immunosensor based on CoMn-LDH for the visualized detection of tylosin.

[Display omitted] • Smartphone-assisted portable biosensor for rapid and visualized detection of TYL. • Bimetallic CoMn-ZIF derived electroactive layered double hydroxide (CoMn-LDH) • High specific surface area, electrochemical activity, and affinity toward antibody. • Ultralow limit of detection, good practicality toward TYL in diverse real samples. The precise and rapid analysis of antibiotics containing in food stuffs is essential for guaranteeing the safety of food products and drinking water. Thus, the sensitive determination of antibiotics is highly urgent. Herein, CoMn-LDH derived from bimetallic CoMn-ZIF was utilized as the sensitive material and ink for modifying the screen-printed electrode (SPE) to manufacture the visualized amperometric immunosensor to detect tylosin (TYL) with the smartphone assistance. Benefiting to the features of CoMn-ZIF, the achieved CoMn-LDH exhibited large specific surface area and pore size, abundant oxygen vacancies, rich and exposed metal sites, high functionality, and core–shell nanostructure with thin shell thickness. Thus, CoMn-LDH illustrated the high adhesive force with the SPE, the improved affinity toward the TYL-targeted antibody and fast electronic response. Thereby, the manufactured CoMn-LDH-based amperometric immunosensor displayed the wide linear range from 1.0 fg mL−1 to 1.0 ng mL−1 with an ultralow detection limit of 0.89 fg mL−1 toward TYL. Also, the developed amperometric immunosensor has demonstrated the good sensing ability of high selectivity, good reproducibility and stability, and accepted regenerated performance, as well as the great potential for the electronic visualized analysis of TYL containing in diverse real samples. This work has provided a new amperometric immunosensing strategy for the efficient analysis of antibiotics in food samples through the visual way. [ABSTRACT FROM AUTHOR]