Simultaneous detection of mixed pesticide residues based on portable Raman spectrometer and Au@Ag nanoparticles SERS substrate

A label-free SERS sensor was successfully developed for simultaneous detection of acetamiprid and thiram using easily synthesized bimetallic core-shell Au@Ag nanoparticles. Au@Ag nanoparticles synthesized by a seed-mediated growth method were used as SERS substrates to realize simultaneous detection of mixed pesticides according to the SERS intensity at 635 (acetamiprid) and 1385 (thiram) cm−1. Complex mixed pesticide systems were established to research the feasibility of simultaneous detection of this SERS sensor. The method showed satisfactory linearity in the range of 5–100 μM and 0.5–10 μM with the limit of detection of 1.22 μM and 0.076 μM for acetamiprid and thiram in apple juice samples, respectively. The recovery for accuracy and precision analysis was 90.2–122.12% in apple juice samples. This SERS detection method combined with portable Raman spectrometer will become a powerful tool for simultaneous testing of multiple contaminants in food safety on-site detection.