title: Target-induced structure switching of hairpin aptamers for label-free and sensitive fluorescent detection of ATP via exonuclease-catalyzed target recycling amplification.
abstract: In this work, we described the development of a new label-free, simple and sensitive fluorescent ATP sensing platform based on exonuclease III (Exo III)-catalyzed target recycling (ECTR) amplification and SYBR Green I indicator. The hairpin aptamer probes underwent conformational structure switching and re-configuration in the presence of ATP, which led to catalytic cleavage of the re-configured aptamers by Exo III to release ATP and to initiate the ECTR process. Such ECTR process resulted in the digestion of a significant number of the hairpin aptamer probes, leading to much less intercalation of SYBR Green I to the hairpin stems and drastic suppression of the fluorescence emission for sensitive ATP detection down to the low nanomolar level. Due to the highly specific affinity bindings between aptamers and ATP, the developed method exhibited excellent selectivity toward ATP against other analogous molecules. Besides, our ATP sensing approach used un-modified aptamer probes and could be performed in a "mix-and-detect" fashion in homogenous solutions. All these distinct advantages of the developed method thus made it hold great potential for the development of simple and robust sensing strategies for the detection of other small molecules.
authors: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors: Yunying
authors: Y
authors: Xu
authors: Jin
authors: J
authors: Xu
authors: Yun
authors: Y
authors: Xiang
authors: Ruo
authors: R
authors: Yuan
authors: Yaqin
authors: Y
authors: Chai
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis*; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism; D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D003959:Diamines; D005090:Exodeoxyribonucleases / Q000378:metabolism; D005456:Fluorescent Dyes / Q000032:analysis*; D057230:Limit of Detection; D009930:Organic Chemicals / Q000032:analysis*; D011804:Quinolines; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D052157:Aptamers, Nucleotide; D052160:Benzothiazoles; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D000255:Adenosine Triphosphate; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III
keywords: Adenosine triphosphate; Hairpin aptamer; Label-free; Signal amplification; Target recycling