Food safety control of zeranol through voltammetric immunosensing on Au–Pt bimetallic nanoparticle surfaces

This study reports an accurate and sensitive strategy for zeranol (ZER) determination in bovine urine samples. ZER is a mycotoxin widely used as a synthetic growth promoter in the livestock production whose residues could present a potential risk for human health. Therefore, its use as an animal feed additive has been banned in most countries. ZER determination was accomplished using an electrochemical system in which bimetallic Au–Pt nanoparticles (Au–PtNPs) were electro-synthesized on a screen-printed carbon electrode (SPCE). The obtained Au–PtNP platform was immunofunctionalized using specific anti-ZER antibodies as a strategy to avoid potential interference. After biorecognition, ZER was directly oxidized and detected by square-wave voltammetry (SWV). The Au–PtNP surface was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and cyclic voltammetry (CV). The limit of detection calculated was 0.01 ng mL−1 with a wide linear range from 0.03 to 30 ng mL−1. This method promises to be suitable for ZER quantification in bovine urine samples ensuring food quality and safety, as well as consumer’s health.