Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7230251 | Biosensors and Bioelectronics | 2016 | 16 Pages |
Abstract
Herein, an aptamer-initiated on-particle template-independent enzymatic polymerization (aptamer-OTEP) strategy for electrochemical aptasensor (E-aptasensor) is developed for analysis of cancer biomarker carcino-embryonic antigen (CEA). A pair of DNA aptamers is employed which can be specifically bond with CEA simultaneously. One of the aptamer is thiolated at 3â²-terminal and immobilized onto the gold electrode as a capture probe, while the other one has a thiol group at its 5â²-terminal and is modified onto the gold nanoparticles surface to form a nanoprobe. In the present of target, the two aptamers can “sandwich” the target, thus the nanoprobe is attached to the electrode. Then terminal deoxynucleotidyl transferase (TdT) is employed to catalyze the incorporation of biotin labeled dNTPs into the 3â²-OH terminals of the DNA aptamer on the nanoprobe. The as-generated long DNA oligo tentacles allow specific binding of numerous avidin modified horseradish peroxidase (Av-HRP), resulting in tens of thousands of HRP catalyzed reduction of hydrogen peroxide and sharply increasing electrochemical signals. Taking advantage of the enzyme based nucleic acid amplification and nanoprobe, this strategy is demonstrated to possess the outstanding amplification efficiency.
Related Topics
Physical Sciences and Engineering
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Authors
Pengjuan Wang, Ying Wan, Shengyuan Deng, Shulin Yang, Yan Su, Chunhai Fan, Ali Aldalbahi, Xiaolei Zuo,