An ultrasensitive aptamer-based fluorescent on/off system for trace amount evaluation of Yersinia enterocolitica in food samples

An innovative aptamer labeled with 5-FAM has been developed with a high affinity for Yersinia enterocolitica (Y. enterocolitica) using graphene oxide (GO) as a quenching platform. The selectivity of the prepared system was evaluated in the presence of common coexisted bacteria like Yersinia pseudotuberculosis, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella typhimurium. Some experimental factors like pH and stability were investigated. The results showed that in the absence of Y. enterocolitica, aptamer labeled with 5-FAM was bonded with GO, causing fluorescence to be relatively weak. After the addition of Y. enterocolitica, the aptamer is released from the GO surface and binds to the target bacteria, and significantly increases the fluorescence intensity with an excitation wavelength of 410 nm and an emission wavelength of 530 nm. After optimizing all conditions, the system exhibited a wide linear response for Y. enterocolitica in the concentration range 10 to 1.0 x 10(9) CFU center dot mL(-1) and the limit of detection (LOD) was 3 CFU center dot mL(-1). This system demonstrated that GO-designed aptamers can be successful in detecting Y. enterocolitica in whole-cell forms, making them potentially useful for screening and rapid detection.

Automated summary

An innovative aptamer labeled with 5-FAM and using graphene oxide (GO) as a quenching platform has been developed for high affinity detection of Y. enterocolitica. The system showed selectivity towards Y. enterocolitica in the presence of other common bacteria. Optimized conditions resulted in a wide linear response range and a low limit of detection, making the system potentially useful for rapid screening of Y. enterocolitica.