Graphene oxide-based biosensor for sensitive fluorescence detection of DNA based on exonuclease III-aided signal amplification

Based on the super fluorescence quenching efficiency of graphene oxide and exonuclease III aided signal amplification, we develop a facile, sensitive, rapid and cost-effective method for DNA detection. In the presence of target DNA, the target-probe hybridization forms a double-stranded structure and exonuclease III catalyzes the stepwise removal of mononucleotides from the blunt 3′ termini of probe, resulting in the recycling of the target DNA and signal amplification. Therefore, our proposed sensor exhibits a high sensitivity towards target DNA with a detection limit of 20 pM, which was even lower than previously reported GO-based DNA sensors without enzymatic amplification, and provides a universal sensing platform for sensitive detection of DNA.

We have developed a novel GO-based biosensor for enzymatic amplified DNA detection. By taking advantage of the super fluorescence quenching efficiency of GO and exonuclease III aided signal amplification, our proposed sensor exhibits a high sensitivity towards target DNA with a detection limit of 20 pM, which was even lower than previously reported GO-based DNA sensors without enzymatic amplification. Moreover, the sensing system is facile, rapid and cost-effective and can provide a universal sensing platform for sensitive detection of various DNA.Figure optionsDownload as PowerPoint slideHighlights
► Graphene oxide (GO) can be prepared in large quantities at very low cost.
► GO can selectively bind and quench a dye-labeled single stranded DNA probe.
► The probe is labeled with a single dye, which reduces the cost for DNA detection.
► Using Exo III can improve the versatility and sensitivity of the DNA assays.
► A sensitive, rapid and cost-effective method for DNA detection has been developed.