Molecular-Recognition-Based DNA Nanodevices for Enhancing the Direct Visualization and Quantification of Single Vesicles of Tumor Exosomes in Plasma Microsamples

Dinggeng He, See Lok Ho, Hei Nga Chan, Huizhen Wang, Luo Hai, Xiaoxiao He*, Kemin Wang, Hung Wing LI

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Citations (Scopus)

Abstract

Tumor exosomes (Exo) are presumed to expedite both the growth and metastasis of tumors by actively participating in nearly all aspects of cancer development. Tumor-derived Exos are thus proposed as a resource for diagnostic biomarkers in bodily fluids. However, most Exo assays require large samples and are time-consuming, complicated, and costly, and thus unsuited for practical applications. Herein, we show an ultrasensitive assay that can directly visualize and quantify tumor Exos in plasma microsamples (1 μL) at the single-vesicle level. The assay uses the specific binding of activatable aptamer probes (AAP) to target Exos captured by Exo-specific antibodies on the surface of a flow cell to produce activated fluorescence. Furthermore, the bound AAP triggers in situ assembly of a DNA nanodevice with enhanced fluorescence that improves the Exo-detection sensitivity. By identifying tyrosine-protein-kinase-like 7 (PTK7), a total-internal-reflection-fluorescence (TIRF) assay for PTK7-Exo distinguishes target tumors from control subjects. This assay is also informative in monitoring tumor progression and early responses to therapy. The developed assay can be readily adapted for diagnosis and monitoring of other disease-associated Exo biomarkers.

Original languageEnglish
Pages (from-to)2768-2775
Number of pages8
JournalAnalytical Chemistry
Volume91
Issue number4
DOIs
Publication statusPublished - 19 Feb 2019

Scopus Subject Areas

  • Analytical Chemistry

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