Orderly Aggregated Catalytic Hairpin Assembly for Synchronous Ultrasensitive Detecting and High-Efficiency Co-Localization Imaging of Dual-miRNAs in Living Cells

Abstract

In this work, the orderly aggregated catalytic hairpin assembly (OA-CHA) was developed for synchronous ultrasensitive detection and high-efficiency colocalization imaging of dual-miRNAs by a carefully designed tetrahedral conjugated ladder DNA structure (TCLDS). Exactly, two diverse hairpin probes were fixed on tetrahedron conjugated DNA nanowires to form the TCLDS without fluorescence response, which triggered OA-CHA in the aid of output DNA 1 and output DNA 2 produced by targets miRNA-217 and miRNA-196a cycle to generate TCLDS with remarkable fluorescence response. Impressively, compared with the traditional CHA strategy, OA-CHA avoided the fluorescence group and quenching group from approaching again because of the spatial confinement effect to significantly enhance the fluorescence signal, resulting in the simultaneous ultrasensitive detection of dual-miRNAs with detection limits of 21 and 32 fM for miRNA-217 and miRNA-196a, respectively. Meanwhile, the TCLDS with lower diffusivity could achieve accurate localization imaging for reflecting the spatial distribution of dual-miRNAs in living cells. The strategy based on OA-CHA provided a flexible and programmable nucleic amplification method for the synchronous ultrasensitive detection and precise imaging of multiple biomarkers and had potential in disease diagnostics..

A Dual-Recognition Fluorescence Enzyme-Linked Immunosorbent Assay for Specific Detection of Intact Lipid Nanoparticles via a Localized Scaffolding Autocatalytic DNA Circuit Amplifier

“…When it comes to sensitive detection, fluorescence-based catalytic hairpin assembly (CHA) is the catalytic circuit, which achieves effective signal amplification for trace detection. − In the CHA reaction, when the cycle time of the original target is too long, it is more attractive to induce more targets by replicating themselves . Wang et al designed an autocatalysis cross-activation reaction of cascade hybridization reaction and CHA to achieve stable intracellular miRNA detection .…”