A fluorescence aptasensor based on two-dimensional sheet metal-organic frameworks for monitoring adenosine triphosphate

In the present study, a facile fluorescence aptasensor based on two-dimensional sheet metal-organic frameworks of N,N-bis(2-hydroxyethyl)dithiooxamidato copper(II) (H(2)dtoaCu) was developed for the sensitive detection of adenosine triphosphate (ATP). The sensing mechanism was based on the non-covalent interaction between FAM-labeled (fluorescein amidite) ATP aptamers and H(2)dtoaCu. In the absence of ATP, the FAM-labeled aptamer readily adsorbs onto H(2)dtoaCu, mainly via pi-pi stacking and hydrogen bond interactions between the nucleotide bases and the H(2)dtoaCu surface, leading to the reduction of fluorescence intensity of the FAM by photoinduced electron transfer (PET). In the presence of ATP, the FAM-labeled aptamer specifically forms ATP-binding aptamer complexes which exhibit only weak adsorption on the H(2)dtoaCu surface. Thus, the fluorescence of the FAM-labeled ATP aptamer remained largely unchanged. The fluorescence aptasensor exhibited a good linear relationship between the fluorescence intensity and the logarithm concentration of ATP over a range of 25-400 nM, with a detection limit of 8.19 nM (3S/N). ATP analogs such as guanosine triphosphate, uridine triphosphate, and cytidine triphosphate have negligible effect on the aptasensor performance due to the high selectivity of the ATP aptamer to its target, showing promising potential in real sample analysis. (C) 2017 Elsevier B.V. All rights reserved.