Enzyme-free dual-DNA walker based on catalytic hairpin assembled DNAzyme for sensing telomerase activity

•An enzyme-free and isothermal dual-DNA walker has been constructed for the ultrasensitive detection of telomerase activity.•The strategy is based on catalytic hairpin assembly walker-transduced DNAzyme walker.•The method shows a lower detection limit of 7 cells mL−1.•The strategy can detect telomer...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Sensors and actuators. B, Chemical Chemical, 2021-02, Vol.329, p.129078, Article 129078
Hauptverfasser: Shen, Yong, Gong, Jiaomei, Li, Shengqiang, Liu, Cuiying, Zhou, Lili, Sheng, Jiahe, Qingxia, Xu
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:•An enzyme-free and isothermal dual-DNA walker has been constructed for the ultrasensitive detection of telomerase activity.•The strategy is based on catalytic hairpin assembly walker-transduced DNAzyme walker.•The method shows a lower detection limit of 7 cells mL−1.•The strategy can detect telomerase activity of cancer cells in human serum with good results. Telomerase is a potential tumor biomarker. Herein, an enzyme-free and isothermal fluorescence strategy, dual-3D DNA walker based on catalytic hairpin assembled DNAzyme (CHA-DNAzyme), for ultrasensitive detection of telomerase activity is described. Upon incubation with telomerase, the telomerase primer is elongated to form telomeric repeat sequences (TR). The elongated TR stochastically moves along the predesign track by continuous strand displacement reaction to assemble the intact DNAzyme (CHA walker). Then, the activated DNAzyme autonomously moves along the other track by cleaving DNA hairpins to release fluorescent-labeled DNA fragments from AuNPs (DNAzyme walker). As a result, a large amount of fluorescence is recovered to analyze telomerase activity. The use of CHA walker and DNAzyme walker endows the sensing strategy with high sensitivity and signal transfer efficiency. The strategy exhibits a wide analytical range from 10 to 1000 HeLa cells mL−¹ with a limit of detection of 7 cells mL−¹. The strategy not only can detect telomerase activity in different tumor cells, but also quantifies telomerase activity of cancer cells from accumulated normal cells. In addition, the practicability of the strategy is validated by detecting telomerase activity in human serum.
ISSN:0925-4005
1873-3077
DOI:10.1016/j.snb.2020.129078