Comparative detection of E. coli, B. subtilis and their mixture in yam samples by ATP bioluminescence and SERS...

Pathogenic bacteria rapid detection is important to ensure food safety and human health. In this study, surface-enhanced Raman spectroscopy (SERS) and adenosine triphosphate bioluminescence (ATP-BL) optical detection platforms were established for evaluating and comparing the performance in the detection of E. coli, B. subtilis and their mixture in yam slices. The results showed that the two techniques significantly reduced the time and cost compared with the traditional culture method. Among them, the detection limits based on SERS were 8.64 CFU/mL, 6.11 CFU/mL and 11.22 CFU/mL for E. coli, B. subtilis and mixed bacteria in actual yam slices, respectively. Accordingly, the detection limits based on ATP-BL were 49.58 CFU/mL, 50.63 CFU/mL and 26.01 CFU/mL, respectively, which demonstrated that both techniques possessed excellent sensitivity and reliability. The results of statistical analysis by t-tests showed that there was no significant difference (P > 0.05) between the two methods and the plate culture method, and the recovery rates were both between 85 %-115 %. In addition, compared to the constructed ATP-BL platform, the SERS method had higher stability, lower detection limit, and shorter time consumption.