Two-color quantum dots-based fluorescence resonance energy transfer for rapid and sensitive detection of Salmonella on eggshells

•A FRET method based on QDs are established for selective and sensitive Salmonella Enteritidis detection.•The wide linear ranges are 75–5 × 105 CFU/mL with a low detection limit of 10 CFU/mL.•This method is satisfactorily applied to analysis of eggshell samples.

In this paper, we report a novel strategy for highly sensitive, rapid, and selective detection of Salmonella Enteritidis using two-color quantum dots based on fluorescence resonance energy transfer (FRET) and fluoroimmunoassay technology. In this FRET system, two-color QDs were adopted as donors and acceptors simultaneously to improve its sensitivity and accuracy. The fluorescence intensity of QDs receptors decreased linearly with the increasing concentrations of S. Enteritidis from 75 to 5 × 105 CFU/mL due to FRET system and fluoroimmunoassay reaction. The limit of detection of S. Enteritidis in this method was 10 CFU/mL without sample enrichment within 1–2 h. This method has been applied to the analysis S. Enteritidis of synthetic samples and eggshell samples. The QDs receptors even can potentially be developed into a sensor for quantitative or qualitative determination of S. Enteritidis in the further.

Graphical abstractIllustration of the principle for the FRET-based two-color QDs immunoassay for detection of Salmonella Enteritidis.Figure optionsDownload full-size imageDownload as PowerPoint slide