Construction of an autocatalysis-driven DNA circuit for highly efficient detection of H5N1 oligonucleotide

Abstract

H5N1 is a highly pathogenic avian influenza virus (AIV) that is a significant risk to both poultry production and human health. The sensitive and reliable determination of H5N1 is thus highly desirable for early antiviral therapy and controlling the outbreak. Isothermal DNA circuits have afforded a promising tool for molecular sensing in complex biological environments, yet are always constrained by their low amplification depth and insufficient signal gain. Herein, a simple-yet-robust autocatalytic DNA circuit (ADC) was devised for highly efficient H5N1 DNA analysis through the synergistic catalysis of catalytic hairpin assembly (CHA) and rolling circle amplification (RCA). The trigger-activated RCA circuit can generate numerous repeated initiators for stimulating the CHA transducer. Meanwhile, the initiator-stimulated CHA circuit can produce the re-assembled RCA trigger to reversely motivate the RCA system. The synergistic cross-activation between the RCA and CHA amplicon can achieve progressive reaction acceleration and exponentially amplified signal gain. The ADC system is highly versatile and capable of reliably detecting H5N1 DNA in buffer and biological samples with high performance, highlighting its great promise for low-abundance biomolecule sensing and early disease diagnosis.