Multi-channel collection of G-quadruplex transducers for amplified signaling of Pax-5 based on target-triggered split-to-intact remodeling of dual-G-rich duplex probe

Abstract

Nucleic acids-sensing methods provide the potential to enable and hasten early disease detection and to rationalize treatments, especially for cancers. In this work, a colorimetric label-free sensing system based on target-triggered split-to-intact remodeling of dual-G-rich duplex probe (Dual-GDP) has been developed for amplified signaling of Pax-5 gene. In this sensing system, the Dual-GDP is splited into one hairpin-structured G-rich probe (HGP) and one duplex-shaped G-rich probe (DGP), which can be re-built to an intact form through target gene triggered accurate base-pairing. Significantly, this unique split-to-intact remodeling behavior allows the occurrence of a well-designed active isothermal amplification that can amplify target response with seven stages to multi-channel accumulate numbers of G-quadruplex transducers. When specifically combined with hemin, the formed G-quadruplex-hemin complexes, also known as DNAzymes, can strongly catalyze the oxidization of TMB to a colored TMB+ and robustly reflect the target gene even in complex biological environments. We demonstrate that this method offers simplified operations and improved assay abilities for Pax5 gene analysis. We envision these findings might provide new insights to exploit versatile oligonucleotide probes and nucleic acid-based amplification strategies for diverse bioanalytical applications.