Based Exonuclease Ⅲ Auxiliary Signal Is Amplified Chemiluminescence Resonance Energy Transfer System Highly Sensitive Detection Of Nucleic Acids

DNA detection has played an important role in the field of medical diagnostics, environmental monitoring, food safety and forensic. Therefore, the development of high sensitivity of DNA detection system has been a hot research topic in analytical chemistry. We established an amplified chemiluminescence biosensing platform for ultrasensitive DNA detection based on exonuclease Ⅲ-assisted target recycling amplification and the super quenching efficiency of graphene oxide.1. The biosensing platform for ultrasensitive DNA detection based on chemiluminescence resonance energy transfer and exonuclease Ⅲ-assisted target recycling amplificationWe reported an amplified chemiluminescence biosensing platform for ultrasensitive DNA detection. It is based on exonuclease Ⅲ-assisted target recycling amplification and the super quenching efficiency of graphene oxide (GO). 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 fluorescein-labeled probe DNA, resulting in the recycling of the target DNA and CL signal amplification of luminol-H2O2-HRP-fluorescein chemiluminescence resonance energy transfer (CRET) system. The detection limit of target DNA was estimated to be as low as9fM, and the sensitivity was about3orders of magnitude better than that of GO-based fluorescence resonance energy transfer (FRET) sensor for DNA with exonuclease Ⅲ-assisted amplification. This CL biosensor offers the advantages of being facile, sensitive, rapid and cost-effective.2. The biosensing platform for ultrasensitive DNA methylation and DNA methyltransferase activity detection based on chemiluminescence resonance energy transfer and exonuclease Ⅲ-assisted target recycling amplificationThe normal cytosine is modified by sodium bisulfite and then converted to uracil, whereas the methylcytosine remains almost unchanged due to its extremely low reactivity, which results in the different construction of nucleic acids sequences. The5’ end of the probe DNA is labeled with fluorescein, and the fluorescein-labeled probe is complementary with the methylated DNA. Then, we established an ultrasensitive, high selectivity, low cost biosensing platform for the detection of DNA methylation and DNA methyltransferase based on the super quenching efficiency of graphene oxide and exonuclease Ⅲ-assisted signal recycling amplification in the luminol-H2O2-HRP-fluorescein chemiluminescence resonance energy transfer system.