Trace Detection of Ciprofloxacin in Milk by Label-Free Raman Enhancement using Two-Dimensional Magnesiochromite

Antibiotic resistance and adverse reactions in humans can be avoided by detecting antibiotics early in the milk supply chain. To meet the demand, we developed a flexible and simple optical sensing method based on a non-van der Waals two-dimensional (2D) metal oxide, 2D-magnesiochromite (2D-MgCr2O4). We used a rapid, label-free Raman enhancement mechanism for antibiotic detection. The Raman spectral mapping method has also been used to quickly identify traces of antibiotics in food products. Here, we have used UV–visible spectroscopy, Raman spectroscopy, and Raman imaging to analyze the 2D material's detection potential in water initially and finally in milk. The device has over a month-long shelf life, even when stored in typical atmospheric conditions, and the acquired detection limits are 30 ng/mL by UV–visible spectroscopy and 10 ng/mL by Raman spectroscopy in milk. Such methods can be extended to detection of other toxic ingredients in food products.