A fluorescent and colorimetric Schiff base chemosensor for the detection of Zn2+ and Cu2+: Application in live cell imaging and colorimetric test kit

Spectrochim Acta A Mol Biomol Spectrosc. 2019 Mar 15:211:34-43. doi: 10.1016/j.saa.2018.11.058. Epub 2018 Nov 23.

Abstract

A novel Schiff base chemosensor HMID, ((E)‑1‑((2‑hydroxy‑3‑methoxybenzylidene)amino)imidazolidine‑2,4‑dione), have been designed and synthesized. Sensor HMID showed a selectivity to Zn2+ through fluorescence enhancement in aqueous solution. Its detection limit was analyzed as 11.9 μM. Importantly, compound HMID could be applied to image Zn2+ in live cells. Detection mechanism of Zn2+ by HMID was suggested to be an effect of chelation-enhanced fluorescence (CHEF) by DFT calculations. Moreover, HMID could detect Cu2+ with a change of color from colorless to pink. The selective detection mechanism of Cu2+ by HMID was demonstrated to be the promotion of intramolecular charge transfer band by DFT calculations. Additionally, HMID could be employed as a naked-eye colorimetric kit for Cu2+. Therefore, HMID has the ability as a 'single sensor for dual targets'.

Keywords: Cell imaging; Chemosensor; Colorimetric; Copper ion; Fluorescent; Zinc ion.

MeSH terms

  • Chelating Agents / chemistry
  • Color
  • Colorimetry / methods*
  • Copper / analysis*
  • Density Functional Theory
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Fluorescent Dyes / metabolism
  • HeLa Cells
  • Humans
  • Limit of Detection
  • Magnetic Resonance Spectroscopy
  • Molecular Imaging / methods*
  • Molecular Structure
  • Schiff Bases / chemistry
  • Spectrometry, Mass, Electrospray Ionization
  • Spectrophotometry, Ultraviolet
  • Zinc / analysis*

Substances

  • Chelating Agents
  • Fluorescent Dyes
  • Schiff Bases
  • Copper
  • Zinc