Multi-functional electrochemiluminescence biosensor for efficient capture, elimination, and sensitive monitoring of Staphylococcus aureus.

In this study, we developed a novel strategy for effective bacteria capture, elimination, and detection. The aptamer of Staphylococcus aureus (S. aureus) was immobilized on FeO NPs and partly hybridized with the T strand, which exhibited good bacterial capture efficiency. Even though high concentration of S. aureus (7.7 × 10 CFU/mL) was introduced, almost all the bacteria were combined on FeO in 60 min. Meanwhile, efficient amplification strategies include strand-displacement reaction, DNA walker, and essential oil-synthesized Au:Ag NPs were developed for the sensitive measurement of the released T strand during the capture of S. aureus. The green-synthesized Au:Ag NPs can effectively kill S. aureus while also significantly improving the ECL signal (16.7-fold). Owing to the outstanding features of Au:Ag NPs, this novel biosensor displayed a wide linear range and a low detection limit for S. aureus measurement. As a result, this multifunctional technique shows great potential for practical applications in the fields of food safety and the environment.