title: Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise.
abstract: A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is the substrate for both ligation and digestion enzyme reaction, was designed. SYBR green I (SG I), a double-stranded specific dye, was applied for the readout fluorescence signal. Exonuclease I (Exo I) and exonuclease III (Exo III), sequence-independent nucleases, were selected to digest the loop DNA probe in order to minimize the background fluorescence signal. As a result, in the absence of ATP, the loop DNA was completely digested by Exo I and Exo III, leading to low background fluorescence owing to the weak electrostatic interaction between SG I and mononucleotides. On the other hand, ATP induced the ligation of the nicking site, and the sealed loop DNA resisted the digestion of Exo I and ExoIII, resulting in a remarkable increase of fluorescence response. Upon background noise reduction, the sensitivity of the ATP determination was improved significantly, and the detection limitation was found to be 1.2 pM, which is much lower than that in almost all the previously reported methods. This strategy has promise for wide application in the determination of ATP.
authors.affiliation: Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University , Xiamen, Fujian 361005, China.
authors.forename: Chunshui
authors.initials: C
authors.lastname: Lin
authors.forename: Zhixiong
authors.initials: Z
authors.lastname: Cai
authors.forename: Yiru
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Zhu
authors.forename: Chaoyong James
authors.initials: CJ
authors.lastname: Yang
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis*; D001483:Base Sequence; D052160:Benzothiazoles; D015342:DNA Probes / Q000737:chemistry*; D003959:Diamines; D005090:Exodeoxyribonucleases / Q000737:chemistry; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D008969:Molecular Sequence Data; D009930:Organic Chemicals / Q000737:chemistry; D011804:Quinolines; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D052160:Benzothiazoles; D015342:DNA Probes; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D000255:Adenosine Triphosphate; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I; C020133:exodeoxyribonuclease III