Fig. 7. (A) SERS spectra of various concentrations of thiram. (B and D) Fitting plots based on Raman intensity at I₅₆₁vs. −log[thiram] and I₁₃₈₆vs. −log[thiram], respectively. (C and E) Calibration plots based on the Raman intensity of I₅₆₁/I₁₀₉₅vs. −log[thiram] and I₁₃₈₆/I₁₀₉₅vs. −log[thiram], respectively. Error bars signify the RSD of 11 spectra collected continuously for 20 s after the occurrence of the optimal hotspots.