Versatile fluorescence detection of T4 PNK and mRNA based on unique DNA nanomachine amplification

The development of DNA nanomachines provides a new strategy for the detection of tumor markers. In this work, an intelligent three-dimensional (3D) DNA walking machine with polynucleotide kinase (PNK) activator was designed, which was coupled with unique nanomachine formed by DNA nanowire cascade amplification reaction for versatile fluorescence detection of T4 PNK activity and messenger RNA (mRNA). When PNK exists, the free DNA walker was formed by hydrolysis cleavage of exonuclease, then the fluorophore-labeled report probe on the Au nanoparticles (NPs) was sheared during cycling cleavage reaction, thus the fluorescence signal was recovered for detection of PNK. Moreover, the DNA nanowires were produced by rolling ring amplification, then target mRNA sequentially initiated interval hybridization of hairpin probes through DNA nanowire, thus realizing DNA cascade reaction (DCR) with high on signal of DNA nanomachine for mRNA assay. This developed novel fluorescence nanomachine reported a new assay method with promising application for versatile targets and showed great potential for molecular-target therapies, and clinic diagnostics.

Automated summary

The development of DNA nanomachines offers a new approach for tumor marker detection. In this study, an intelligent three-dimensional DNA walking machine coupled with a unique nanomachine was designed for versatile fluorescence detection of T4 PNK activity and mRNA. The DNA nanomachine consisted of a free DNA walker and DNA nanowire cascade amplification reaction, enabling sensitive and specific detection of PNK and mRNA. This novel fluorescence nanomachine holds promise for versatile target detection and potential applications in molecular-targeted therapies and clinical diagnostics.