Computational ionophore selection during optimization of a portable calixarene based sensor for direct assay of levamisole residues in livestock products

[Display omitted] •Portable solid-state potentiometric sensor for rapid, direct assay of levamisole.•Experimental and computation optimization of the sensor composition.•Assay of levamisole residues in bovine milk, muscles, kidney, and liver samples.•Assessment of the entire method for greenness. Poor practices in the livestock industry include the misuse of veterinary drugs to promote production and enhance the feed transformation ratio. The drugs accumulate in the edible tissues and transfer to consumers imposing health hazards. For instance, levamisole (LVM) residues lead to health hazards (e.g. hematological toxicity and agranulocytosis). Accordingly, authorities have drawn strict limits for LVM residues in edible tissues. This work introduces the first portable solid-contact potentiometric sensor for direct LVM assay in multiple bovine products. The sensor included a drop-casted membrane cocktail over a polyaniline coated glassy-carbon substrate. An initial study optimized the membrane cocktail composition for maximum sensitivity and selectivity. Molecular docking supported the experimental results for ionophore selection. The optimized sensor engendered a Nernstian response with a LOD of 1.56 × 10−6 M. The greenness of the developed method was assessed using the National Environmental Method Index pictogram. The method was officially validated; and successfully determined LVM in bovine milk, muscle, kidney, and liver samples. Quality control laboratories can use the portable sensor for LVM overuse surveillance.