Sensitive Electrochemical Aptamer Biosensor for Dynamic Cell Surface N-Glycan Evaluation Featuring Multivalent Recognition and Signal Amplification on a Dendrimer鈥揋raphene Electrode Interface
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- 作者：Xiaojiao Chen ; Yangzhong Wang ; Youyu Zhang ; Zhuhai Chen ; Yang Liu ; Zhaolong Li ; Jinghong Li
- 刊名：Analytical Chemistry
- 出版年：2014
- 出版时间：May 6, 2014
- 年：2014
- 卷：86
- 期：9
- 页码：4278-4286
- 全文大小：403K
- 年卷期：v.86,no.9(May 6, 2014)
- ISSN：1520-6882
文摘
We demonstrate a multivalent recognition and highly selective aptamer signal amplification strategy for electrochemical cytosensing and dynamic cell surface N-glycan expression evaluation by the combination of concanavalin A (Con A), a mannose binding protein, as a model, conjugated poly(amidoamine) dendrimer on a chemically reduced graphene oxide (rGO鈥揇EN) interface, and aptamer- and horseradish peroxidase-modified gold nanoparticles (HRP鈥揳ptamer鈥揂uNPs) as nanoprobes. In this strategy, the rGO鈥揇EN can not only enhance the electron transfer ability but also provide a multivalent recognition interface for the conjugation of Con A that avoids the weak carbohydrate鈥損rotein interaction and dramatically improves the cell capture efficiency and the sensitivity of the biosensor for cell surface glycan. The high-affinity aptamer- and HRP-modified gold nanoparticles provide an ultrasensitive electrochemical probe with excellent specificity. As proof-of-concept, the detection of CCRF-CEM cell (human acute lymphoblastic leukemia) and its surface N-glycan was developed. It has demonstrated that the as-designed biosensor can be used for highly sensitive and selective cell detection and dynamic evaluation of cell surface N-glycan expression. A detection limit as low as 10 cells mL鈥? was obtained with excellent selectivity. Moreover, this strategy was also successfully applied for N-glycan expression inhibitor screening. These results imply that this biosensor has potential in clinical diagnostic and drug screening applications and endows a feasibility tool for insight into the N-glycan function in biological processes and related diseases.