Antibody-powered DNA switches to initiate the hybridization chain reaction for the amplified fluorescence immunoassay
| Autor: | Zehui Chen, Hui-Lin Deng, Ruo Yuan, Wenju Xu, Jia-Yang He |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Fluorophore
DNA Single-Stranded Biosensing Techniques 02 engineering and technology 010402 general chemistry 01 natural sciences Biochemistry Analytical Chemistry Mice chemistry.chemical_compound Limit of Detection Dig Electrochemistry Animals Environmental Chemistry Nanodevice Spectroscopy Fluorescent Dyes Immunoassay biology Nucleic Acid Hybridization DNA 021001 nanoscience & nanotechnology 0104 chemical sciences chemistry Helix biology.protein Biophysics Antibody 0210 nano-technology Hapten Chain reaction |
| Zdroj: | The Analyst. 146:5067-5073 |
| ISSN: | 1364-5528 0003-2654 |
| DOI: | 10.1039/d1an01045j |
| Popis: | Designing antibody-powered DNA nanodevice switches is crucial and fascinating to perform a variety of functions in response to specific antibodies as regulatory inputs, achieving highly sensitive detection by integration with simple amplified methods. In this work, we report a unique DNA-based conformational switch, powered by a targeted anti-digoxin mouse monoclonal antibody (anti-Dig) as a model, to rationally initiate the hybridization chain reaction (HCR) for enzyme-free signal amplification. As a proof-of-concept, both a fluorophore Cy3-labeled reporter hairpin (RH) in the 3' terminus and a single-stranded helper DNA (HS) were individually hybridized with a recognition single-stranded DNA (RS) modified with Dig hapten, while the unpaired loop of RH was hybridized with the exposed 3'-toehold of HS, isothermally self-assembling an intermediate metastable DNA structure. The introduction of target anti-Dig drove the concurrent conjugation with two tethered Dig haptens, powering the directional switch of this DNA structure into a stable conformation. In this case, the unlocked 3'-stem of RH was implemented to unfold the 5'-stem of the BHQ-2-labeled quench hairpin (QH), rationally initiating the HCR between them by the overlapping complementary hybridization. As a result, numerous pairs of Cy3 and BHQ-2 in the formed long double helix were located in spatial proximity. In response to this, the significant quenching of the fluorescence intensity of Cy3 by BHQ-2 was dependent on the variable concentration of anti-Dig, achieving a highly sensitive quantification down to the picomolar level based on a simplified protocol integrated with enzyme-free amplification. |
| Databáze: | OpenAIRE |
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