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Updated: Aug 6, 2026
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Rapid Fluorescence-based Characterization of Single Extracellular Vesicles in Human Blood with Nanoparticle-tracking Analysis
Published on: January 7, 2019
A dual-recognition fluorescence chip utilizing a substrate-borne DNA walker for precision profiling of small
Xiaoya Liu1, Xianxian Zhao2, Xiang Zhang1
1Department of Oncology, Key Laboratory of Immunity, Inflammation & Cancer (Chongqing Municipal Health Commission), The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
Biosensors & Bioelectronics
|July 17, 2026
Summary
We developed a novel DNAzyme walker on extracellular vesicles for sensitive detection. This bipedal walker enhances signal amplification and reduces false positives for improved diagnostics.
Area of Science:
- Biotechnology
- Nanotechnology
- Molecular Diagnostics
Background:
- Small extracellular vesicles (sEVs) are crucial biomarkers, but their detection is challenging.
- Existing DNAzyme walkers often use nanoparticle supports and single-arm designs.
- Limitations include lower sensitivity and potential for false positives.
Purpose of the Study:
- To develop a highly sensitive and specific fluorescence chip for detecting sEVs.
- To engineer a novel bipedal DNAzyme walker on sEVs membranes.
- To improve signal amplification and reduce non-specific binding in sEV detection.
Main Methods:
- Assembled a membrane-anchored, bipedal DNAzyme walker on sEVs using catalytic hairpin assembly (CHA).
- Utilized dual recognition of sEV lipid bilayer and EpCAM protein for specificity.
- Integrated the reaction cascade onto a chip platform for point-of-care testing.
Main Results:
- Achieved a theoretical detection limit of 2.8 particles/μL, surpassing single-arm walkers.
- Demonstrated superior signal amplification due to the bipedal architecture.
- Eliminated false positives using dual recognition and showed robust performance in serum samples (99.1-103.8% recovery).
Conclusions:
- Established a CHA-assisted, bipedal DNAzyme walker mechanism on biological membranes.
- This approach offers a new paradigm for designing DNA nanomachines for membrane-enveloped targets.
- The developed chip shows potential for accurate and reproducible point-of-care diagnostics.
