A nanozipper structured efficient FRET probe for ratiometric detection of ATP based on target-induced cycling amplification

Abstract

In the realm of disease diagnostics and prognostics, accurate quantification of adenosine triphosphate (ATP) has become crucial, as the intricate interplay between ATP and cellular metabolism is a fundamental factor in the pathogenesis and progression of many pathological conditions. Herein, a ratiometric fluorescence DNA nanozipper is developed, which enables highly sensitive detection of ATP by employing catalytic hairpin assembly. This innovative approach utilizes target-induced conformational changes in the nanozipper structure to tune the distance between the carboxyfluorescein as donor and tetramethylrhodamine as acceptor around the Förster radius, thereby enhancing the efficiency of fluorescence resonance energy transfer (FRET). In the state of nanozipper tension, the rigid and steric hindrance Y-shaped configuration leads to a considerable distance between two fluorophores, resulting in FRET low efficiency. However, the presence of ATP triggers allosteric configuration of the DNA nanozipper, switching the nanozipper to a relaxed state, which results in a visible fluorescent ratiometric signal. The sensing strategy exhibits a linear response to ATP concentrations in the range of 30 − 600 nM and can detect concentrations as low as 9.6 nM. Additionally, this detection method introduces a novel idea for the design of efficient FRET probes and demonstrates promising application potential in biological samples.