Optimum synthesis of Au@Ag nanoparticle as plasma amplifier to detect trace concentration of AFB1 via object-binder-metal SERS method

The problem of aflatoxin contamination emerged gradually in the field of food safety. Surface-enhanced Raman spectroscopy (SERS) is an ultra-sensitive and non-destructive spectroscopy technology with extensive application prospects in the detection field. In this paper, with the detection of AFB1 as the target, Au@Ag NPs substrate with uniform morphology and strong SERS effect was prepared. Furthermore, the intermediates formed by hydrogen bonding between AFB1 and melamine facilitate the binding of toxin molecules to the substrate. Moreover, the AFB1-melamine-Au@Ag NPs detection system was established by optimizing the melamine dosage, and the limit of detection can reach 10-8 mol/L (M). In this method, AFB1 (concentration range of 10-4 M-10-7 M) in tea oil, the Raman signal intensity of AFB1 shows an excellent linear, logarithmic relationship, and the correlation coefficient is 0.9685. Therefore, this work has achieved simple, sensitive, and stable AFB1 detection and has broad application potential in food safety detection.