Rapid detection of tetracycline residues at clinically relevant levels via a novel, inexpensive and analytically-sensitive magneto-immunoassay – A feasibility study

Expensive, time-consuming and labour-intensive solvent-extraction and liquid-chromatography methods are the industry's current gold standard for antibiotic residue quantification. A novel immunoassay methodology and system for the rapid detection of clinically relevant levels of tetracycline residues found in food-producing animal tissues is described. Anti-tetracycline antibody-coated paramagnetic particles were used for the specific capture of tetracycline in spiked buffer (with and without a 1% pork muscle tissue suspension) and quantified via an analytically-sensitive in-house magnetometer instrument. Detection of tetracycline between 0.1 μg/mL - 1 μg/mL was achieved, with a readout time (including sample treatment) presented in 20 min. The magneto-immunoassay described provides a rapid, low-cost, de-skilled and analytically-sensitive solution for tetracycline screening at the point-of-sampling, with potential applications for other prevalent antibiotic families used in the international farming and food industry.