Development of quantum-dot-encapsulated liposome-based optical nanobiosensor for detection of telomerase activity without target amplification

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• 作者：Ali Zavari-Nematabad…
• 关键词：Telomerase ; CdTe QDs ; Signal amplification ; Liposome ; Fluorescence
• 刊名：Analytical and Bioanalytical Chemistry
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：409
• 期：5
• 页码：1301-1310
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Analytical Chemistry; Biochemistry, general; Laboratory Medicine; Characterization and Evaluation of Materials; Food Science; Monitoring/Environmental Analysis;
• 出版者：Springer Berlin Heidelberg
• ISSN：1618-2650
• 卷排序：409

文摘

Reactivation of telomerase, which is observed in more than 85% of all known human tumours, is considered a promising tumour marker for cancer diagnosis. With respect to the biomedical importance of telomerase, we have developed a simple strategy based on liposomal fluorescent signal amplification for highly sensitive optical detection of telomerase activity using liposome-encapsulated cadmium telluride quantum dots. In this strategy, telomerase extracted from A549 cells elongated the biotinylated telomerase substrate primer, which was then immobilized on streptavidine-coated microplate wells. After the hybridization of the telomerase-elongated product with biotinylated capture probe, streptavidin was added to the assembly. In the next step, biotinylated liposome was conjugated with capture probe through streptavidin. Finally, QD-encapsulated liposomes were disrupted by Triton X-100, and the fluorescence intensity of the released QDs was measured to detect telomerase activity. The results showed that the proposed nanobiosensor was able to detect telomerase activity from as few as 10 A549 cells without the enzymatic amplification of telomerase extension products. In short, this method is not only convenient and sensitive, but also has a simple operating protocol and a wide detection range (10–5000 cells). A linear range was observed between 50 and 800 cells with a correlation coefficient of 0.982 and regression equation of y = 0.0444 x + 17.137. The proposed method is economical, more user-friendly, without error-prone PCR, with a wide detection range and simple operating protocol without the requirement for sophisticated equipment.