A Sensitive Surface-Enhanced Raman Spectroscopy Method for Detecting Tetracycline in Milk

Tetracycline, an animal antibiotic, may remain in milk to cause harm to human health. For economic reasons, the abuse of antibiotics is becoming more and more common. Therefore, the abuse of tetracycline has alarmed the dairy industry and many countries such as New Zealand, China, and the USA have proposed strict standards. Surface-enhanced Raman scattering (SERS) is an emerging detection method which has been applied in food detection with the advantages of no complex pretreatment, fast detection, and weak water environment interference. Considering the abuse of antibiotics in dairy industry, we used polydimethylsiloxane (PDMS) plasma cavity as SERS substrate to detect tetracycline in milk. We found that the enhancement ability of PDMS substrate is affected by addition of 4-amino-1-butanol and complex interplay in the milk--tetracycline system. The modified PDMS plasma cavity has high SERS sensitivity that allows us to achieve low detection limit of 0.28 μg/L. The correlation coefficient was 0.987. The detection of tetracycline in milk using PDMS substrate is quick (within 10 min) and it provides a possible method for in-site detection of tetracycline.