title: A sensitive electrochemical aptasensor for ATP detection based on exonuclease III-assisted signal amplification strategy.
abstract: 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 0.1-20 nM 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.
authors: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors: Ting
authors: T
authors: Bao
authors: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors: Huawei
authors: H
authors: Shu
authors: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors: Wei
authors: W
authors: Wen
authors: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China.
authors: Xiuhua
authors: X
authors: Zhang
authors: Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules & College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, PR China. Electronic address: wangsf@hubu.edu.cn.
authors: Shengfu
authors: S
authors: Wang
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis* / Q000378:metabolism*; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D055162:Biocatalysis; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques; D004566:Electrodes; D005090:Exodeoxyribonucleases / Q000378:metabolism*; D005453:Fluorescence; D054856:G-Quadruplexes; D009693:Nucleic Acid Hybridization
chemical_list: D052157:Aptamers, Nucleotide; D000255:Adenosine Triphosphate; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III
keywords: Adenosine triphosphate; Aptamer; Electrochemical aptasensor; Exonuclease III; Signal amplification