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摘要
A novel method based on both insertion approach for the repeatability improvement and the dual-hairpin structure as a signal amplifier for the sensitivity improvement was investigated for adenosine triphosphate (ATP) detection. For the preparation of the aptasensor, the moiety and methylene blue (MB) labeled aptamer probe were inserted into a loosely packed cyclic-dithiothreitol (DTT) monolayer, and the MB labeled adjunct probe could hybridize with the aptamer probe to form the dual-hairpin structure on the electrode. In the absence of the target, the stable dual-hairpin conformation enabled the MB to stay close to the electrode surface, generating a strong current signal. However, when the target was introduced, the high affinity binding of aptamer/target complex kept the MB of aptamer probe distanced from the electrode surface and forced the adjunct probe to dissociate from the modified electrode, decreasing the current signal obviously. The current intensity was inversely proportional to the concentration of ATP in the range of 5 nM to 1 mu M with a detection limit of 1.4 nM. Moreover, our method is highly selective toward ATP and can be applied in more bioanalytical systems.
- 出版日期2016-1
- 单位西南大学
