Rapid Detection of Salmonella enteritidis Based on Aptamer Raman Spectroscopy

Objectives:SELEX technology was used to screen high affinity and high specificity aptamer,and the rapid detection method of Salmonella enteritidis was established by using this aptamer combined with Raman spectroscopy. Methods:The specific aptamers of Salmonella enteritidis were screened by the ligand system evolution technology with bacterial index enrichment. The affinity and specificity of the aptamers were evaluated by enzyme-linked immunosorbent assay and SERS technology,and the detection method of Salmonella enteritidis was established. Results:In this study,aptamer₄,aptamer₁₀,and aptamer₁₂ as three candidate aptamers were selected through 15 rounds of SELEX screening for Salmonella enteritidis,and their affinity were evaluated by ELISA. Aptamer₄ was confirmed as the best aptamer by SERS technology. Aptamer₄ was combined with 5 kinds of mixed bacteria such as Salmonella enteritis and Klebsiella pneumoniae. The results showed that Salmonella enteritidis could be detected specifically and the repeatability of this method was good. The lowest detection limit of bacterial concentration was 10² CFU/mL. The recovery of Salmonella enteritidis was 93.37%~100.18%. Conclusion:SELEX method was used to screen out the suitable ligands with high specificity and affinity for Salmonella enteritidis,and a rapid detection method for Salmonella enteritidis based on surface enhanced Raman spectroscopy was established. This method had strong specificity,high sensitivity,low cost,fast and simple,so that it could be used for the rapid detection of Salmonella enteritidis in food processing.