Abstract
In this work, a fluorescence aptasensor has been developed to detect trace chloramphenicol based on FRET and exonuclease-assisted target recycling. Firstly, the composite probe for CAP was prepared through the immunoreactions between the capture probe based on dsDNA antibody labeled on Fe3O4@Au nanoparticles and the nanotracer using double strand aptamer (aptamer hybrid with its complementary DNA) labeled on core-shell SiO2@Au. When the composite probe solution was mixed with CAP, the aptamer on the nanotracer preferentially bounded with CAP, and then released cDNA-SiO2@Au and CAP-Apt complex to the supernatant. This is because anti-DNA on capture probes can’t recognize the ssDNA. The exonuclease I (Exo I) added into the supernatant can further digest the aptamer-CAP from the 3′-end of aptamer and release CAP again, which can further participate in new cycle to react with the probes. The supernatant containing numerous SiO2@Au could efficiently quench the fluorescence response of CdSe QDs by FRET. Experimental results showed the CAP detection owning a linearity range of 0.001–10ngmL−1 and detection of limit (LOD) of 0.0002ngmL−1. Besides, the results of our method for CAP detection in the fish samples agreed well with those from ELISA, verifying its accuracy and reliability.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.