Digital droplet technology has emerged as a powerful new tool for biomarker analysis. Temperature cycling, enzymes, and off-chip processes are, nevertheless, always required. Herein, we constructed a digital droplet auto-catalytic hairpin assembly (ddaCHA) microfluidic system to achieve digital quantification of single-molecule microRNA (miRNA).
View Article and Find Full Text PDFThe synthesis of multi-walled carbon nanotubes (MWCNTs) was carried out over different Ni-loaded metallic oxide catalyst nanoparticles and under different reduction times to control the outside diameter of the nanotubes. Moreover, high-purity, free-standing membranes were fabricated by a simple filtration of the as-grown MWCNTs. Furthermore, the dye-adsorption properties of the nanotubes depended on the diameter of the carbon nanotubes (CNTs).
View Article and Find Full Text PDFIn this work, a novel DNA nanostructure with a shorter assembly time and larger loading capacity was constructed using amphiphilic DNA-alkane group (Spacer C12) conjugates encapsulating plentiful fat-soluble fluorescent dyes into the hydrophobic core to form the DNA micelles, which could be rapidly self-disassembled via target induced hydrophilic-hydrophobic regulation to release fluorescent dyes from micelles to the organic phase, realizing the fast and sensitive detection of microRNA.
View Article and Find Full Text PDFThe evident contradiction between high local-concentration-based substrate reactivity and free-diffusion-based high reaction efficiency remains one of the important challenges in chemistry. Herein, we propose an efficient aggregation-induced synergism through the hydrophobic-driven self-assembly of amphiphilic oligonucleotides to generate high local concentration whereas retaining high reaction efficiency through hydrophobic-based aggregation, which is important for constructing efficient DNA nanomachines for ultrasensitive applications. MicroRNA-155, used as a model, triggered strand displacement amplification of the DNA monomers on the periphery of the 3D DNA nanomachine and generated an amplified fluorescent response for its sensitive assay.
View Article and Find Full Text PDFHerein, by anchoring cholesterol-labelled DNA probes to silicon-supported lipid bilayers via cholesterol-lipid interaction, a dynamic three-dimensional (3D) DNA nanostructure could be facilely assembled, which is applied as a microRNA (miRNA)-induced self-powered 3D DNA nanomachine with high movement efficiency. Once the self-powered 3D DNA nanomachine is triggered by target miRNA, it achieves autonomous operation without external addition of fuel DNA strands or protein enzymes. Impressively, the biocompatible lipid bilayers not only preserve the biological character of the DNA probes, but also improve the movement efficiency of the DNA nanomachine, which directly solves the key challenge of the steric barrier effect of traditional rigid surfaces (Au or silicon) for DNA probe diffusion.
View Article and Find Full Text PDFIn this work, a novel fluorescent assay was proposed for the ultrasensitive detection of microRNA-21 (miRNA-21) based on the efficient immobilization of protoporphyrin IX (PPIX) as signal indicators in massive G-quadruplex structures obtained by target recycling, three-dimensional DNA walker and a rolling circle amplification (RCA) coupled cascade nucleic acid amplification strategy.
View Article and Find Full Text PDF