Versatile Electrochemiluminescence Biosensing Platform Based on DNA Nanostructures and Catalytic Hairpin Assembly Signal Amplification

Abstract

Achieving rapid and highly sensitive detection of biomarkers is crucial for disease diagnosis and treatment. Here, a highly sensitive and versatile dual-amplification electrochemiluminescence (ECL) biosensing platform was constructed for target detection based on DNA nanostructures and catalyzed hairpin assembly (CHA). Specifically, when the target DNA was present, it would hybridize with the auxiliary strands (D1 and D2) to form an I-shaped nanostructure, which in turn triggered the subsequent catalytic hairpin assembly reaction to generate plenty of double-stranded DNA complexes (H1–H2). The resulting double-stranded complex could be trapped on the electrode surface and adsorbed the ECL signal probe Ru­(phen)3 2+.We found that the I-shaped nanostructure-triggered CHA reaction had higher amplification efficiency compared with traditional CHA amplification. Thus, a sensitive “signal-on” ECL biosensor was constructed for target DNA detection with a detection limit of 1.09 fM. Additionally, by combining the binding properties of C–Ag+–C with an elaborately designed “Ag+-helper” probe, the proposed strategy could be immediately utilized for the highly sensitive and selective detection of silver ions, demonstrating the versatility of the developed biosensing platform. This strategy provided a new approach with potential applications in disease diagnosis and environmental monitoring.

High-Density N-Vacancy-Induced Multipath Electrochemiluminescence Improvement of 3D g-C3N4 for Ultrasensitive MiRNA-222 Analysis

“…As some targets could not be directly detected or the targets were extremely low in abundance for detection, the target conversion biosensor had very important research significance. , Realizing effective target amplification in solution and reducing the background signal on the electrode were two key aspects for improving the sensitivity of target conversion biosensor. Various DNA amplification techniques were widely used in the target conversion and signal amplification in solution, such as rolling circle amplification (RCA), catalytic hairpin assembly (CHA), and hybridization chain reaction (HCR). , Among them, HCR had good application prospects due to its advantages of simple operation and being enzyme-free. , However, traditional HCR reaction efficiency is not sufficiently high enough because its kinetics depend on the diffusion of random collisions and interactions of DNA reactants in a homogeneous environment, which needs to be improved urgently. − Fixing the DNA involved in the reaction on a long DNA chain in an ordered manner to assemble comblike DNA nanostructures may enable the HCR reaction to reduce the diffusion process and hybridize more orderly to increase the reaction efficiency. Meanwhile, the background signal of the electrode was also the key to affecting the sensitivity of this kind of biosensor.…”

Flexible Self-Powered Sensing System Based on Novel DNA Circuit Strategy and Graphdiyne for Thalassemia Gene by Rapid Naked-Eye Tracking and Open-Circuit Voltage

“…In traditional CHA reactions, a single hairpin is formed into a double-stranded structure triggered by the target molecule, followed by subsequent cycles. , By introduction of a DNA initiator strand into a single CHA reaction, a dual-catalyst hairpin assembly system is constructed. The addition of the DNA initiator strand enhances the reaction efficiency and improves the reaction kinetics. , …”

CRISPR-Cas12a Coupled with DNA Nanosheet-Amplified Fluorescence Anisotropy for Sensitive Detection of Biomolecules

“…However, the sensitivity of this DNS-amplified FA strategy needs to be further improved because a target just can cause an FA change of one fluorophore group. In some traditional biosensing methods, catalytic hairpin assembly (CHA), , hybridization chain reaction (HCR), − polymerase chain reaction (PCR), − and other cyclic amplification technologies − are usually used to improve the sensitivity. However, these cyclic amplification technologies require specialized instruments and technicians and were more complex to operate than methods that do not require cyclic amplification.…”