Rapid detection of tilmicosin residues in duck blood by surface-enhanced Raman spectroscopy

To achieve the detection of tilmicosin residues in duck blood, this paper adopts surface-enhanced Raman spectroscopy (SERS) technology combined with chemometric methods to construct a rapid detection model for tilmicosin residues. In the study, density functional theory (DFT) was used to calculate the theoretical Raman spectrum of tilmicosin. The detection conditions were optimized through single-factor experiments, covering key parameters such as sample pretreatment, types and dosages of electrolyte aggregating agents, dosage of gold nano-colloid, and adsorption time. The experimental results showed that the limit of quantitation for tilmicosin in duck blood was 0.50 mg/L, and the optimal spectral pretreatment method was the adaptive iteratively reweighted penalized least squares (air-PLS);the optimal feature extraction method was Principal Component Analysis (PCA); the coefficient of determination for the prediction set (Rp2) reached 0.9202, the root mean square error of the prediction set (RMSEP) was 3.3273 mg/L, and the relative prediction deviation (RPD) was 3.1317. The above research results indicated that the SERS method could achieve rapid detection of tilmicosin residues in duck blood.