Ultra-high SERS-active nanowires-PTFE composite substrate for trace detection of Aflatoxin B₁ in aquaculture water

Aflatoxin B₁ (AFB₁), a potential carcinogen distributed in aquaculture systems, threatens aquatic health and food safety. However, current methods for detecting AFB1 in aquaculture water still rely on time-consuming sample pretreatment and costly large-scale instruments. Herein, we developed a high-performance surface-enhanced Raman scattering (SERS) sensor based on ultra-active silver nanowires (U-AgNWs) for AFB₁ quantification in aquaculture water. PTFE substrate with hydrophobic condensation effect were selected to enhance SERS signal. Self-assembled AgNWs at the three-phase (oil-water-gas) interface were added onto the PTFE substrate. Subsequently, AgNWs were etched with aqua regia to increase surface roughness. Following iterative refinement, a novel PTFE substrate with remarkable SERS activity was successfully fabricated. This hybrid structure with significant SERS enhancement had been validated through FDTD simulation, and subsequent experiments had confirmed that the sensor had anti-interference, reproducibility, and repeatability. The sensor exhibited excellent linearity (R² > 0.97) for AFB₁ within the range of 0.1ng/mL-10⁴ng/mL and had satisfactory performance in aquaculture with recoveries of 97.3 %-103.2 % (reference HPLC/LM-MS). This sensor provides a simple, highly sensitive, and selective strategy for the timely detection of AFB₁ in aquaculture, thus contributing to the security of aquatic products, the safeguarding of ecosystems, and the protection of public health. And this work also paved a way for developing facile devices to detect antibiotics, heavy metals, and other targets.