A sensitive electrochemical aptasensor for ATP detection based on exonuclease III-assisted signal amplification strategy

作者：Bao Ting; Shu Huawei; Wen Wei; Zhang Xiuhua; Wang Shengfu^*

来源：Analytica Chimica Acta, 2015, 862: 64-69.

DOI：10.1016/j.aca.2014.12.049

• Aptamer
• Electrochemical aptasensor
• Exonuclease III
• Signal amplification
• Adenosine triphosphate

A target-induced structure-switching electrochemical aptasensor for sensitive detection of ATP was successfully constructed which was based on exonuclease III-catalyzed target recycling for signal amplification. With the existence of ATP, methylene blue (MB) labeled hairpin DNA formed G-quadruplex with ATP, which led to conformational changes of the hairpin DNA and created catalytic cleavage sites for exonuclease III (Exo III). Then the structure-switching DNA hybridized with capture DNA which made MB close to electrode surface. Meanwhile, Exo III selectively digested aptamer from its 3'-end, thus G-quadruplex structure was destroyed and ATP was released for target recycling. The Exo III-assisted target recycling amplified electrochemical signal significantly. Fluorescence experiment was performed to confirm the structure-switching process of the hairpin DNA. In fluorescence experiment, AuNPs-aptamer conjugates were synthesized, AuNPs quenched fluorescence of MB, the target-induced structure-switching made Exo III digested aptamer, which restored fluorescence. Under optimized conditions, the proposed aptasensor showed a linear range of 0.1-20nM with a detection limit of 34 pM. In addition, the proposed aptasensor had good stability and selectivity, offered promising choice for the detection of other small molecules.

• 出版日期2015-3-3
• 单位湖北大学