Target-induced duplex–triplex transition for ratiometric detection of adenosine triphosphate
| Autor: | Xiujuan Cui, Shujuan Yao, Ling Li, Jianqiang Du, Yanhua Gao, Kaixian Zhang, Donghua Ni, Wen Wang |
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| Rok vydání: | 2017 |
| Předmět: |
Detection limit
Analyte biology General Chemical Engineering Aptamer General Engineering Analytical chemistry 02 engineering and technology Buffer solution 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Fluorescence 0104 chemical sciences Analytical Chemistry chemistry.chemical_compound chemistry biology.protein Biophysics Bovine serum albumin 0210 nano-technology Biosensor Adenosine triphosphate |
| Zdroj: | Analytical Methods. 9:3244-3248 |
| ISSN: | 1759-9679 1759-9660 |
| DOI: | 10.1039/c7ay00507e |
| Popis: | Compared with conventional binding pairs of antigens and antibodies, facile chemical synthesis and generally impressive target selectivity make aptamers an ideal recognition tool for designing various biosensors. Herein, we developed a new ratiometric aptamer sensor based on an aptamer/target-binding-induced duplex–triplex transition. This sensor is composed of a capture strand (CS) modified with a BHQ2 at the 3′ end, a triplex-forming middle strand (MS) modified with TAMRA at the 3′ end, and a target-specific aptamer strand (AS) modified with FAM at the 5′ end. In the absence of analyte, the CS probe could hybridize with both the AS probe at the 3′ end and the MS probe at the 5′ end. As BHQ2 and FAM were in close proximity, the mixed solution showed low FAM fluorescence and high TAMRA fluorescence. After introducing the target molecule ATP, target/aptamer binding split from the duplex helix and liberated the end of the CS probe to fold back and form a triplex helix. Meanwhile, the FAM fluorescence could be recovered, and the TAMRA fluorescence could be quenched due to the close proximity of TAMRA and BHQ2. The intensity ratio (FFAM/FTAMRA) was linear for ATP concentrations of 0.1–10 μM in buffer solution. The detection limit was determined as 65 nM, based on three times the signal-to-noise ratio. The sensor was also applied to ATP sensing in bovine serum, obtaining a good recovery and demonstrating the practicality of this ratiometric aptamer sensor. |
| Databáze: | OpenAIRE |
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