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A Sensitive Aptasensor Based on a Hemin/G‐Quadruplex‐Assisted Signal Amplification Strategy for Electrochemical Detection of Gastric Cancer Exosomes
Author(s) -
Huang Rongrong,
He Lei,
Xia Yanyan,
Xu Hongpan,
Liu Chang,
Xie Hui,
Wang Su,
Peng Lijun,
Liu Yufeng,
Liu Yuan,
He gyue,
Li Zhiyang
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201900735
Subject(s) - aptamer , microvesicles , horseradish peroxidase , detection limit , exosome , hemin , cancer , deoxyribozyme , chemistry , cancer research , nanotechnology , microbiology and biotechnology , materials science , biology , biochemistry , medicine , chromatography , enzyme , microrna , heme , gene
Emerging evidence indicates that exosomes derived from gastric cancer cells enhance tumor migration and invasion through the modulation of the tumor microenvironment. However, it remains a major problem to detect cancer‐specific exosomes due to technical and biological challenges. Most of the methods reported could not achieve efficient detection of tumor‐derived exosomes in the background of normal exosomes. Herein, a label‐free electrochemical aptasensor is presented for specific detection of gastric cancer exosomes. This platform contains an anti‐CD63 antibody modified gold electrode and a gastric cancer exosome specific aptamer. The aptamer is linked to a primer sequence that is complementary to a G‐quadruplex circular template. The presence of target exosomes could trigger rolling circle amplification and produce multiple G‐quadruplex units. This horseradish peroxidase mimicking DNAzyme could catalyze the reduction of H 2 O 2 and generate electrochemical signals. This aptasensor exhibits high selectivity and sensitivity toward gastric cancer exosomes with a detection limit of 9.54 × 10 2 mL −1 and a linear response range from 4.8 × 10 3 to 4.8 × 10 6 exosomes per milliliter. Therefore, this electrochemical aptasensor is expected to become a useful tool for the early diagnosis of gastric cancer.