Enhanced response of benzo[6]urils sustained by graphene oxide for umbelliferones and its applications for quantitative detection of diquat

Abstract

The composites of benzo[6]uril-hybridized graphene oxide were realized with the full characterization of atomic force microscopy (AFM), Infrared spectroscopy (IR), and Raman spectroscopy, which exhibited dramatical improvement of the fluorescence response to the supramolecular interactions of umbelliferones with the macrocyclic compounds to produce the ternary supramolecular hybrid materials, and the host-guest interactions were evidenced with 1H NMR, fluorescence titrations, and molecular simulations to confirm the encapsulation of the umbelliferone guests within the cavities of the macrocyclic hosts. The supramolecular materials were applied for quantitative determination for diquat to give the limits of detection of 3.4 × 10−7 mol L−1 and 5.0 × 10−7 mol L−1, respectively, with high selectivity in coexistence of other bipyridyl interferences including 2,2′-bipyridine, 4,4′-bipyridine, and methyl viologen in aqueous solutions.