Rapid and Quantitative Detection of Aflatoxin B in Grain by Portable Raman Spectrometer.

Many foodstuffs are extremely susceptible to contamination with aflatoxins, in which aflatoxin B is highly toxic and carcinogenic. Therefore, it is crucial to develop a rapid and effective analytical method for detecting and monitoring aflatoxin B in food. Herein, a surface-enhanced Raman spectroscopic (SERS) method combined with QuEChERS (quick, easy, cheap-effective, rugged, safe) sample pretreatment technique was used to detect aflatoxin B. Sample preparation was optimized into a one-step extraction method using an Au nanoparticle-based solution (Au sol) as the SERS detection substrate. An affordable portable Raman spectrometer was then used for rapid, label-free, quantitative detection of aflatoxin B levels in foodstuffs. This method showed a good linear log relationship between the Raman signal intensity of aflatoxin B in the 1-1000 µg L concentration range with a limit of detection of 0.85 µg kg and a correlation coefficient of 0.9836. Rapid aflatoxin B detection times of ∼10 min for wheat, corn, and protein feed powder samples were also achieved. This method has high sensitivity, strong specificity, excellent stability, is simple to use, economical, and is suitable for on-site detection, with good prospects for practical application in the field of food safety.