Water-stable nickel-based coordination polymer for selective and sensitive enhancing and quenching fluorescence sensing of ascorbic acid and acetylacetone

The novel Ni-based coordination polymer [Ni(H2edda) (bpe)] (CP 1 ) was successfully synthesized by em-ploying 5,5 ' (ethane-1,2-diylbis(oxy)) diisophthalic acid (H4edda) and 1,2-bis (4-pyridyl) ethylene (bpe) under hydrothermal conditions. Structural analysis indicates that CP 1 presents a 2-fold-interpenetrated two-dimensional (2 D) framework with a uninodal sql topology. Further investigation reveals that the newly obtained CP can be stable in water or even exposed in a certain acid/base aqueous solution (pH = 3-11) for a long period of time. Remarkably, CP 1 can further serve as a bifunctional sensor for ascorbic acid (AA) and acetylacetone (acac) in aqueous media according to fluorescence enhancing and quenching effects, respectively. Notably, both sensing processes are labeled with exceptional anti -interference property, high sensitivity and selectivity, wide linear range (0-50 mu M for AA and 0.2-1.8 mM for acac) and low detection limit (1.37 nM for AA and 1.58 mu M for acac). Theoretical simulations and ex-perimental findings point out that in the process of AA detection by CP 1 , the significant fluorescence enhancement could be caused by the photo-induced electron transfer (PET) process, while the inner fil-ter effect (IFE) mechanism combined with PET should be responsible for the fluorescence quenching of CP 1 by acac.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, a novel Ni-based coordination polymer with stable and bifunctional sensing capability was successfully synthesized. It exhibited excellent stability in water and had high sensitivity and selectivity for the detection of ascorbic acid and acetylacetone.