A dual-selective fluorescent probe for GSH and Cys detection: Emission and pH dependent selectivity

Anal Chim Acta. 2017 Nov 15:993:87-95. doi: 10.1016/j.aca.2017.09.028. Epub 2017 Sep 28.

Abstract

A novel fluorescent probe 1 based on acridine orange was developed for the selective detection and bioimaging of biothiols. The probe exhibits higher selectivity and turn-on fluorescence response to cysteine (Cys), homocysteine (Hcy), and glutathione (GSH) than to other amino acids. Importantly, the probe responds to GSH and Cys/Hcy with distinct fluorescence emissions in PBS buffer at pH of 7.4. The Cys/Hcy-triggered tandem SNAr-rearrangement reaction and GSH-induced SNAr reaction with the probe led to the corresponding amino-acridinium and thio-acridinium dyes, respectively, which can discriminate GSH from Cys/Hcy through different emission channels. Interestingly, Cys finishes the tandem reaction with the probe and subsequently forms amino-acridinium and Hcy/GSH induces SNAr reaction with the probe to form thio-acridiniums at weakly acidic conditions (pH 6.0), enabling Cys to be discriminated from Hcy/GSH at different emissions. Finally, we demonstrated that probe 1 can selectively probe GSH over Cys and Hcy or Cys over GSH and Hcy in HeLa cells through multicolor imaging.

Keywords: Acridine orange; Cell imaging; Cys; Detection; Fluorescent probe; GSH.

MeSH terms

  • Cysteine / analysis*
  • Fluorescent Dyes*
  • Glutathione / analysis*
  • HeLa Cells
  • Homocysteine / analysis
  • Humans
  • Spectrometry, Fluorescence

Substances

  • Fluorescent Dyes
  • Homocysteine
  • Glutathione
  • Cysteine