A novel bionic magnetic SERS aptasensor for the ultrasensitive detection of Deoxynivalenol based on “dual antennae” nano-silver

Deoxynivalenol (DON), as a mycotoxin produced by Fusarium, showed great harm to human body, crops and animals, so it is urgent to establish an efficient, sensitive and selective method for the detection of DON. Here, a novel bionic magnetic SERS aptasensor based on "dual antennae" nano-silver was designed. β-CD@AgNPs was modified 4-MBA and the aptamers respectively with chemical bond and host-guest interaction, which was reflected in the "dual antennae" characteristics of identifying target and SERS signal label. In addition, Fe3O4@Au was conjugated with SH- modified complementary DNA to prepare capture probes, enabling fast magnetic separation of the captured target and further enhanced Raman scattering. With the specific recognition and competitive binding of DON and aptamer, the combination of "dual antenna" signal probe and capture probe is significantly reduced, exerting a lower SERS intensity. There was a good linear relationship in the range of 0.0001-100 ng mL-1 between the SERS intensity and the logarithm of DON concentration, and the limit of detection (LOD) was as low as 0.032 pg mL-1. The SERS aptasensor exhibited good selectivity, satisfactory repeatability and expected practicability, presenting a great application prospect in the detection of mycotoxins and biochemical analysis.