SERS aptasensor detection of aflatoxin B1 based on silicon-au-ag Janus nanocomposites

Aflatoxin B1 (AFB1) is a prevalent contaminant in maize, posing significant threats to human health. This study designed AuAg Janus NPs with intrinsic Raman signals as signal probes and SiO₂@AgNPs as capture probes. The two were coupled through complementary base pairing to ensure the ordered, controlled distribution of noble metal nanoparticles. The AuAg Janus NPs and the highly stable SiO₂ carrier is expected to avoid the adverse effects on stability caused by using signal molecules and the formation of random aggregates when using the noble metal nanoparticle gap effect to concentrate on the electromagnetic field. This study improved the negative impact of AgNPs' high surface energy on their uniformity, while enhancing the pH adaptability of AuAg Janus NPs. In the presence of AFB1, the composite disintegrates, and the SERS intensity showed a negative correlation with AFB1 concentration, enabling highly sensitive and stable detection of AFB1.