Selective ATP recognition by boronic acid-appended cyclodextrin and a fluorescent probe supramolecular complex in water

Abstract

Various organic compound-based chemosensors for adenosine triphosphate (ATP) have been reported; however, the conventional designs have problems with their water solubility, selectivity, and sensitivity. Herein, a supramolecular complex of boronic acid-appended γ-cyclodextrin and zinc-dipicolylamine-based pyrene probe (Zn-1/FBγCyD) was designed based on the concept of a “cyclodextrin (CyD)-based supramolecular chemosensor”. As a proof-of-concept, we have demonstrated that this complex exhibits a turn-on fluorescence response to ATP in water at physiological pH with excellent selectivity and sensitivity, owing to the efficient self-assembly of Zn-1/FBγCyD with ATP through synergistic interactions to afford a strongly fluorescent product. Remarkably, Zn-1/FBγCyD demonstrated extremely strong affinity for ATP with the conditional formation constant of (7.71 ± 0.09) × 10⁶ M⁻¹, resulting in the low limit of detection of 18.9 nM. Furthermore, Zn-1/FBγCyD can monitor changes in ATP concentration after the addition of apyrase, hydrolysing ATP to adenosine monophosphate and a phosphate ion. We believe that the presented approach of a CyD-based supramolecular chemosensor will propose a novel design that realises unexplored selectivity in the research field of fluorescent molecular recognition.