An Amphiphilic Pyridinoyl-hydrazone Probe for Colorimetric and Fluorescence pH Sensing.
Rosita DianaBarbara PanunziAngela TuziStefano PiottoSimona ConcilioUgo CarusoPublished in: Molecules (Basel, Switzerland) (2019)
A new pH sensor based on a substituted aroylhydrazide with a flexible side chain and a terminal trimethyl ammonium group (PHA+) was designed and synthesized. The terminal quaternary ammonium guarantees excellent solubility in water. At the same time, the probe is very soluble in hydrophobic envirornments. The pyridinoyl-hydrazone moiety acts as the pH-sensitive fluorophore/chromophore probe. Extensive physicochemical characterization has been performed on the bromide salt PHABr. DFT calculations, based on single-crystal X-ray data, permitted to rationalize the optical behavior. Molecular dynamics simulations permitted to clarify the mode of interaction with lipid membrane. The ability of the probe to change color and fluorescence in response to different pH and media of different polarity has been investigated. PHABr shows a remarkable pH-dependent behavior in both absorption and fluorescence spectra with high sensitivity and strong on-off switch effect at neutral pH, perceptible even to the naked eye.
Keyphrases
- molecular dynamics simulations
- living cells
- single molecule
- molecular docking
- fluorescent probe
- quantum dots
- density functional theory
- high resolution
- ionic liquid
- energy transfer
- gold nanoparticles
- molecular dynamics
- computed tomography
- machine learning
- sensitive detection
- hydrogen peroxide
- big data
- fatty acid
- high speed
- oxide nanoparticles