Target-Induced 3D DNA Network Structure as a Novel Signal Amplifier for Ultrasensitive Electrochemiluminescence Detection of MicroRNAs

Abstract

Here, a target-induced three-dimensional DNA network structure (T-3D Net) produced by catalytic hairpin assembly (CHA) was proposed as a novel signal amplifier to fabricate an ultrasensitive electrochemiluminescence (ECL) biosensor for microRNAs detection. Usually, conventional CHA can produce only one output DNA in each target cycle, while the proposed strategy could produce multiple output DNA by using DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) to form T-3D Net. Then, the T-3D Net with high loading capacity could be completely collapsed by dissolving AuNPs to efficiently convert trace microRNA-21 into a large amount of output DNA. Furthermore, the nanocomposite containing Ru­(bpy)3 2+ as luminophore and boron nitride quantum dots (BNQDs) as coreactant provided a strong initial ECL response owing to the short electron transfer distance between luminophore and coreactant (signal-on). Next, the DNA duplex probes labeled with N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and dopamine (DA) (S1-ABEI/S2-DA) were further immobilized on the nanocomposite to reduce the background signal due to the double quenching effect of DA for both ABEI and Ru­(bpy)3 2+ (signal-off). In the presence of the output DNA with enzyme-assisted self-recycling, S2-DA was displaced and detached from the electrode surface to achieve ECL signal recovery. Simultaneously, S1-ABEI restored a stable hairpin structure, making ABEI close to the electrode surface for more effective resonance energy transfer (RET) between ABEI and Ru­(bpy)3 2+, which greatly improved the final ECL response (signal-super on). Thus, the ECL biosensor demonstrated superior performance for ultrasensitive detection of microRNA-21 with low detection limit (0.33 aM) and was successfully applied to monitor the expression of microRNA-21 in human cancer cell lysates. This strategy provided an ultrasensitive way for the detection of biomolecules and revealed an effective avenue for diseases diagnosis.

Programmable High‐Speed and Hyper‐Efficiency DNA Signal Magnifier

“…The DNA strand H2 was labeled with RuBpy (Ru) when as an ECL signal tag Electrochemiluminescence (ECL) biosensor construction according to previous literature. [57] Apparatus and Measurements: Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and SWV were accomplished by using a CHI760E electrochemical workstation (CH Instruments, Shanghai, China) with a three-electrode arrangement. PAGE was conducted by a Bio-Rad imaging system (Hercules, CA).…”

“…The DNA strand H2 was labeled with RuBpy (Ru) when as an ECL signal tag Electrochemiluminescence (ECL) biosensor construction according to previous literature. [ 57 ]…”

Gold Nanoparticles Photosensitization towards 3,4,9,10-Perylenetetracarboxylic Dianhydride Integrated with a Dual-Particle Three-Dimensional DNA Roller: A General “ON–OFF–ON” Photoelectric Plasmon-Enhanced Biosensor

“…Fabrication of the Dual-Particle 3D DNA Roller. AS3-Au NCs, 24 MBs-AS2, MBs-H1, and MBs-track 25 were prepared according to the literature (see Supporting Information). PNR cycle: the same volumes of AS1 (300 nM), MBs-AS2 (5 μM), miRNA 1246 with various concentrations, KF polymerase (0.75 U/μL), Nb.…”

Exploring the Trans-Cleavage Activity of CRISPR/Cas12a on Gold Nanoparticles for Stable and Sensitive Biosensing

“…Besides, the detection sensitivity and response range can be adjusted by tuning the surface coverage of SNAs . These features enable the wide applications of SNAs in molecular diagnostics. − Therefore, if the SNA is introduced as a reporter, it is possible to develop CRISPR-Dx with stronger stability and higher sensitivity. However, although many results have been reported related to the trans-cleavage activity toward ssDNA in solution, researchers know little about the activity on the nanoparticle surface.…”