Abstract:
Human maybe get poisoning after eating
Salmonella choleraesuis-infected food. Thus,developing a new analytical technology for rapid and sensitive detection of
Salmonella choleraesuis in food is urgently needed. Hence,a pH responded colorimetric enzyme-linked immunosorbent assay(pH-ELISA)was developed for sensitive detection of
Salmonella choleraesuis in milk. In this method,glucose oxidase(GOx)was used to catalyze glucose for the generation of gluconic acid. The color of bromocresol purple(BCP)was changed from purple to bright yellow because the pH of sample solution decreased. Under the optimal conditions,the proposed method achieved two linear independent regression equations. When
Salmonella choleraesuis concentration increased from 2.54×10
3 to 6.17×10
5 CFU/mL,the first regression equation was described as y
1=0.1051ln(x)+0.7024(
R2=0.7513). With the increase of
Salmonella choleraesuis concentration from 6.17×10
5 to 1.67×10
7 CFU/mL,the second regression equation was expressed as y
2=1.3216ln(x)-15.797(
R2=0.9711). The average recoveries of the proposed method for spiked milk samples at
Salmonella choleraesuis concentrations ranging from 2.5×10
3~5.6×10
6 CFU/mL were 72.16%~103.58% with the relative standard deviations ranging from 7.54%~15.30%. In conclusion,the developed colorimetric ELISA is suitable for the rapid and sensitive quantitation of
Salmonella choleraesuis in milk.