10.1021/ac050165w.s004 Jun Wang Jun Wang Yaxin Jiang Yaxin Jiang Cuisong Zhou Cuisong Zhou Xiaohong Fang Xiaohong Fang Aptamer-Based ATP Assay Using a Luminescent Light Switching Complex American Chemical Society 2005 acid aptamers protein detection Ru luminescence change ATP detection model target ATP binding recognition probes method DNA biosensor development Luminescent Light Switching Complex multistep analysis 1 nM dppz 2005-06-01 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Aptamer_Based_ATP_Assay_Using_a_Luminescent_Light_Switching_Complex/3283588 With the increasing applications of nucleic acid aptamers as a new class of molecular recognition probes in bioanalysis and biosensor development, the development of general and simple signaling strategies to transduce aptamer−target binding events to detectable signals is demanding. We have developed a new signaling method based on aptamers and a DNA molecular light switching complex, [Ru(phen)<sub>2</sub>(dppz)]<sup>2+</sup>, for sensitive protein detection. In this work, we have demonstrated the applicability of this signaling mechanism to small-molecule detection using ATP as a model target. Our results have shown that upon ATP binding to the folded aptamer where [Ru(phen)<sub>2</sub>(dppz)]<sup>2+</sup> intercalated, the conformational change or distortion of the aptamer is large enough to cause a significant luminescence change of [Ru(phen)<sub>2</sub>(dppz)]<sup>2+</sup>. By monitoring the ATP-dependent luminescence intensity change, we have achieved ATP detection with high selectivity and high sensitivity down to 1 nM in homogeneous solution. The method is very simple without the needs for covalently labeling aptamers or using costly enzymes and multistep analysis as other reported fluorescence/luminescence assays for ATP. The successful detection of ATP indicates that using the signaling aptamers with [Ru(phen)<sub>2</sub>(dppz)]<sup>2+</sup> is expected to be a general method for aptamer-based target detection.