A fluorogenic probe based on chelation-hydrolysis-enhancement mechanism for visualizing Zn2+ in Parkinson's disease models

J Mater Chem B. 2019 Apr 14;7(14):2252-2260. doi: 10.1039/c8tb03343a. Epub 2019 Feb 5.

Abstract

Developing efficient methods for the real-time detection of Zn2+ levels in biological systems is highly relevant to improving our understanding of the role of Zn2+ in the progression of Parkinson's disease (PD). In this work, a novel Schiff base based Zn2+ fluorescent probe (ZP) was designed, synthesized and systematically investigated. A significant turn-on effect on ZP upon the addition of Zn2+ was observed, accompanied by a blue-shift of the fluorescence spectra. ZP is sensitive to Zn2+ and has excellent selectivity against various biologically relevant cations, anions and amino acids. The sensing mechanism of ZP was studied by 1H NMR, MS, single crystal X-ray diffraction and theoretical calculations. The results showed that the response of ZP to Zn2+ was based on the chelation-hydrolysis-enhancement process. Upon bonding, Zn2+ hydrolyzes the Schiff base to an aldehyde precursor, the resulting aldehyde further coordinates to Zn2+ to form a more stable heterobimetallic complex leading to the emission enhancement and blue-shift. ZP was applied to imaging exogenous/endogenous Zn2+ in live HeLa cells. Furthermore, we successfully measured the Zn2+ levels using in vitro PD models, which provided a visualization method to better understand the relationship between Zn2+ levels and PD development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Disease Progression
  • Fluorescent Dyes* / chemical synthesis
  • Fluorescent Dyes* / chemistry
  • HeLa Cells
  • Humans
  • Parkinson Disease / diagnostic imaging*
  • Schiff Bases / chemistry*
  • Spectrometry, Fluorescence / methods
  • Zinc / chemistry*

Substances

  • Fluorescent Dyes
  • Schiff Bases
  • Zinc