Magnetic Microsphere Based Droplet Microarray for High-Throughput Screening of Multiple Chemical Residues in Milk

Abstract

The mycotoxins and antibacterial agents’ residues in animal-derived foods have potential hazards on human health. In this paper, aflatoxins, sulfonamides, fluoroquinolones and lincosamides were selected as model analytes, and we introduce a novel quadplex droplet microarray format for simultaneous screening of multiple chemical residues in milk samples. The droplet microarray relies on micro-volume shallow-well microplate combined with microspheres-based suspension array. In the new established droplet microarrays, the sample usage and the consumption of immuno-reagents was reduced by 80%.  While, the antigen-antibody binding process can be completed in as little as 5 minutes. The limit of detection was evaluated to be 0.023 µg/kg for aflatoxin M1, 5.68 µg/kg for sulfamethoxazole, 0.85 µg/kg for ciprofloxacin, and 2.65 µg/kg for lincomycin. The newly developed droplet microarray has been demonstrated with good validity and sensitivity by comparing it with the conventional immunoassays and instrumental methods.

Keywords: Mycotoxins, antibacterial agents, droplet microarray, quadplexed immunoassay, food safety