Screening melamine contaminant in eggs with portable surface-enhanced Raman Spectroscopy based on gold nanosubstrate

A novel fast ultra-sensitive approach was developed herein to identify melamine contaminant in eggs using portable compact surface-enhanced Raman Spectroscopy (SERS) on gold nanosubstrates. Trace amounts of melamine spiked in albumen and yolk were characterized and quantified by SERS with partial least squares (PLS) analysis, good models were acquired for melamine in albumen at concentration range of 2.5-100 mg/kg with the determination coefficient of actual concentration versus predicted concentration R2 = 0.94, the root mean standard error of cross validation RMSECV = 12.38, the limit of detection (LOD) 1.1 mg/kg, and in yolk 5.0-200 mg/kg with R2 = 0.98, RMSECV = 12.14, LOD = 2.1 mg/kg, respectively. The assay was rapid in less than 30 min, and the detection was sensitive. As a fast screening scheme, the method could be suitably applied to the domain of on-site egg products quality control and market surveillance thereof.