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A nuclease-assisted label-free aptasensor for fluorescence turn-on detection of ATP based on the in situ formation of copper nanoparticles

Song, Quanwei, Wang, Ruihua, Sun, Feifei, Chen, Hongkun, Wang, Zoumengke, Na, Na, Ouyang, Jin
Biosensors & bioelectronics 2017 v.87 pp. 760-763
DNA, adenosine triphosphate, biosensors, copper, cost effectiveness, detection limit, fluorescence, nanoparticles, oligonucleotides, thymine
Owing to their promising advantages in biochemical analysis, aptamer-based sensing systems for the fluorescence detection of important biomolecules are being extensively investigated. Herein, we propose a turn-on fluorescent aptasensor for label-free detection of adenosine triphosphate (ATP) by utilizing the in situ formation of copper nanoparticles (CuNPs) and the specific digestion capability of exonuclease I (Exo I). In this assay, the addition of ATP can effectively hinder the digestion of aptamer-derived oligonucleotides due to the G-quadruplex structure. Accordingly, the remaining poly thymine at 5′-terminus of substrate DNA can serve as an efficient template for red-emitting fluorescent CuNPs with a Mega-Stokes shifting in buffered solution, which can be used to evaluate the concentration of ATP. This method is cost-effective and facile, because it avoids the use of traditional dye-labeled DNA strands and complex operation steps. Under optimized conditions, this method achieves a selective response for ATP with a detection limit of 93nM, and exhibits a good detection performance in biological samples.