Label-Free and Turn-on Aptamer Strategy for Cancer Cells Detection Based on a DNA鈥揝ilver Nanocluster Fluorescence upon Recognition-Induced Hybridization
详细信息 查看全文
- 作者：Jinjin Yin ; Xiaoxiao He ; Kemin Wang ; Fengzhou Xu ; Jingfang Shangguan ; Dinggeng He ; Hui Shi
- 刊名：Analytical Chemistry
- 出版年：2013
- 出版时间：December 17, 2013
- 年：2013
- 卷：85
- 期：24
- 页码：12011-12019
- 全文大小：595K
- 年卷期：v.85,no.24(December 17, 2013)
- ISSN：1520-6882
文摘
We present here a label-free and turn-on aptamer strategy for cancer cell detection based on the recognition-induced conformation alteration of aptamer and hybridization-induced fluorescence enhancement effect of DNA鈥搒ilver nanoclusters (DNA鈥揂g NCs) in proximity of guanine-rich DNA sequences. In this strategy, two tailored DNA probes were involved. One is designed as a hairpin-shaped structure consisting of a target specific aptamer sequence at the 3鈥?end, a guanine-rich DNA sequence, and an arm segment at the 5鈥?end (denote as recognition probe). The other, serving as a signal probe, contains a sequence for Ag NCs templated synthesis and a link sequence complementary to the arm segment of the recognition probe. Recognizing and binding of the aptamer to cancer cells enforces the recognition probe to undergo a conformational alteration and then initiates hybridization between the arm segment of the recognition probe and the link sequence of the signal probe. The Ag NCs are then close to the guanine-rich DNA, leading to an enhanced fluorescence readout. As proof-of-concept, the CCRF-CEM cancer cell detection were performed by using the specific aptamer, sgc8c. It was demonstrated that this strategy could specially image the CCRF-CEM cells. Determination by flow cytometry allowed for detection of as low as 150 CCRF-CEM cells in 200 渭L binding buffer. The general applicability of the strategy is also achieved in the successful detection of Ramos cells. These results implied that this strategy holds considerable potential for simple, sensitive, universal, and specific cancer cell detection with no required washing and separation steps.