1. An electrochemiluminescent aptasensor for amplified detection of exosomes from breast tumor cells (MCF-7 cells) based on G-quadruplex/hemin DNAzymes.
- Author
-
Qiao B, Guo Q, Jiang J, Qi Y, Zhang H, He B, Cai C, and Shen J
- Subjects
- 3-Mercaptopropionic Acid chemistry, Aptamers, Nucleotide metabolism, Biomarkers blood, Biomarkers metabolism, Biosensing Techniques methods, Breast Neoplasms diagnosis, Cadmium Compounds chemistry, Carbon chemistry, DNA metabolism, DNA, Catalytic genetics, DNA, Catalytic metabolism, Electrochemical Techniques instrumentation, Electrochemical Techniques methods, Electrodes, Europium chemistry, Exosomes metabolism, G-Quadruplexes, Hemin metabolism, Humans, Hydrogen Peroxide chemistry, Limit of Detection, Luminescent Measurements methods, MCF-7 Cells, Sulfides chemistry, Aptamers, Nucleotide chemistry, DNA chemistry, DNA, Catalytic chemistry, Exosomes chemistry, Hemin chemistry, Metal Nanoparticles chemistry
- Abstract
Exosomes are non-invasive biomarkers for cancer diagnosis. Herein, we describe an electrochemiluminescent (ECL) aptasensor for the detection of exosomes from breast tumor cells. Mercaptopropionic acid (MPA)-modified Eu
3+ -doped CdS nanocrystals (MPA-CdS:Eu NCs) and H2 O2 were used as ECL emitters and coreactant, respectively. The exosomes are recognized and captured by the CD63 aptamer, and then form a G-quadruplex/hemin DNAzyme, which efficiently catalyzes the decomposition of H2 O2 , resulting in the decreased ECL signal of MPA-CdS:Eu NCs. The exosomes from breast tumor cells (MCF-7 cells) can be detected in the range of 3.4 × 105 to 1.7 × 108 particles per mL. The limit of detection (LOD) was estimated to be 7.41 × 104 particles per mL at a signal-to-noise ratio of 3. The aptasensor has been successfully used to detect exosomes in the serum.- Published
- 2019
- Full Text
- View/download PDF