Ladder-Like DNA Nanostructure-Mediated Cascade Catalytic Nanomachine for Construction of Ultrasensitive Biosensors

Abstract

Herein, a novel two-dimensional ladder-like DNA nanostructure (LDN)-mediated cascade catalytic nanomachine (LDN–CCN) with a higher catalytic efficiency beyond those of a conventional one-dimensional hybrid chain reaction (HCR) nanostructure-mediated CCN was constructed and applied to design an electrochemical biosensing platform with first-rank performance for ultrasensitive detection of target miRNA-21. First, output DNA S1′ and S2′ were produced through the DNAzyme recycle amplification when the target miRNA-21 existed. Then, the controllable LDN–CCN was constructed on S1–S2 modified electrodes by the subsequent reaction triggered by S1′ and S2′ with H1-AuNPs, H2, H3-AuNPs, and H4 with the assistance of K+ and hemin, in which the hemin/G-quadruplexes could produce a prominent electrochemical signal response to the substrate glucose. The best performance of cascade catalysis was acquired when the distance of Au nanoparticles (glucose oxidase-like activity) modified on H1 and H3 and hemin/G-quadruplexes (peroxidase-like activity) formed by the sticky ends of H2 and H4 was roughly 9 nm (27 bp) in LDN–CCN. The constructed electrochemical platform realized the sensitive detection of target miRNA-21 with the linear range from 100 aM to 10 nM and with a detection limit as low as 48.5 aM, which provided novel insights to explore the new functional DNA nanostructure and well-performing mimic enzyme cascade catalytic platforms for applications in biological fields and early diagnosis of diseases.

Nucleic acid isothermal amplification-based soft nanoarchitectonics as an emerging electrochemical biosensing platform

“…32 Furthermore, in order to have better sensitivity to trace targets, some recent electrochemical sensors combine HCR with other nucleic acid amplification technologies. [33][34][35] For example, using target-induced Mg 2+specific DNAzyme amplification in solution, a novel twodimensional ladder-like HCR reaction was designed, which showed higher catalytic efficiency than those of a traditional HCR reaction with a lower detection limit of 48.5 aM miRNA21. 33 In addition, DNA tool enzyme (Nicking endonuclease and polymerase) assisted cascade amplification 34 and CRISPR processing technology 35 could also be combined in the HCR amplification method for dual signal amplified genetic analysis.…”

“…[33][34][35] For example, using target-induced Mg 2+specific DNAzyme amplification in solution, a novel twodimensional ladder-like HCR reaction was designed, which showed higher catalytic efficiency than those of a traditional HCR reaction with a lower detection limit of 48.5 aM miRNA21. 33 In addition, DNA tool enzyme (Nicking endonuclease and polymerase) assisted cascade amplification 34 and CRISPR processing technology 35 could also be combined in the HCR amplification method for dual signal amplified genetic analysis. Besides the solid electrode, using carbon ink screen printing technology, the architecture for DNA strand displacement amplification could also be constructed on microfluidic cloth-based 36 or paper-based analytical devices 37 for point-of-care (POC) diagnosis in resource-limited settings, avoiding the cumbersome chip fabrication and high-cost peripheral facilities.…”