A phenolphthalein-based fluorescent probe for the sequential sensing of Al3+ and F- ions in aqueous medium and live cells

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Feb 5:208:131-139. doi: 10.1016/j.saa.2018.09.064. Epub 2018 Oct 6.

Abstract

A novel fluorescent probe, phenolphthalein‑dialdehyde‑(2‑pyridyl) hydrazone (L), for sequentially detecting Al3+ and F- in almost 100% aqueous medium was successfully designed and synthesized. The probe offers two binding pockets for Al3+ to form a 1: 2 ligand/metal complex, leading to a significant fluorescence enhancement at 465 nm. Further, the in-situ formed L-Al complex acts as a secondary fluorescent chemosensor for F- by quenching the fluorescence of the complex with high selectivity. The detection limit for Al3+ and F- sensing is 2.28 nM and 0.13 μM, respectively, which are far below the World Health Organization (WHO) acceptable limits (7.41 μM for Al3+ ion and 79 μM for F-) in drinking water. The probe L was successfully applied to the detection of Al3+ and F- in cells using fluorescence microscopy.

Keywords: Aqueous medium; Cell imaging; Fluorescent probe; Sequential sensing.

MeSH terms

  • Aluminum / analysis*
  • Anions
  • Cell Line, Tumor
  • Cell Survival
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Fluorides / analysis*
  • Humans
  • Hydrogen-Ion Concentration
  • Phenolphthalein / chemistry*
  • Proton Magnetic Resonance Spectroscopy
  • Spectrometry, Fluorescence
  • Spectrophotometry, Ultraviolet
  • Spectroscopy, Fourier Transform Infrared
  • Water / chemistry*

Substances

  • Anions
  • Fluorescent Dyes
  • Water
  • Phenolphthalein
  • Aluminum
  • Fluorides