Figure 6.

(A) SERS spectra of APT with different concentrations of 10²–10⁻³ ng/cm² collected from the surface of apple peels and the Raman spectrum of APT powder; (B) Raman intensity of APT from apple peels samples at 1577 cm⁻¹ by using Au/DW substrate (linear calibration plot between the Raman intensity and acephate concentrations); (C) SERS spectra of 10 ng/cm² APT collected from 5 apple peels samples via the “press and peel off” method by using the Au/DW substrate; (D–F) the main Raman vibrational intensities of 10 ng/cm² APT at characteristic Raman peaks (D: 1078 cm⁻¹; E: 1390 cm⁻¹; F:1577 cm⁻¹).