Wiley, Journal of Physical Organic Chemistry, 7(37), 2023
DOI: 10.1002/poc.4581
Full text: Unavailable
AbstractOne colorimetric and one fluorescent‐indicator displacement assay (IDA) were studied to assess their interaction with methyl viologen (MV), an herbicide commercially known as paraquat. The host–guest complexes formed by cucurbit[7]uril (CB[7]) and the 4‐nitroaniline (NA) or Berberine (Be) dyes function as colorimetric‐ and fluorescent‐IDA for MV, respectively. The CB[7]@NA and CB[7]@Be complexes were characterized by UV–vis, fluorescence spectroscopy, and dynamic simulations. Isothermal titration calorimetry (ITC) experiments and dynamic simulations were employed to obtain thermodynamic data for the formation of the 1:1 inclusion complexes. Finally, NA is proposed as a reference colorimetric dye for determining CB[7]‐binding affinities using competitive host–guest titrations, and the fluorescent‐IDA as the best assay proposed, as it exhibits a high binding constant, a good detection limit of 2.7 × 10−6 mol L‐1, good linearity in the range from 4 × 10−6 mol L‐1 to 3.5 × 10−5 mol L‐1, in aqueous solution.