A highly specific and ultrasensitive probe for the imaging of inflammation-induced endogenous hypochlorous acid

Analyst. 2019 Jun 7;144(11):3546-3551. doi: 10.1039/c9an00390h. Epub 2019 May 1.

Abstract

A turn-on two-photon fluorescent probe HCA-Green for hypochlorous acid (HOCl) was synthesized using 4-methylamino-1,8-naphthalimide (MNA) as a two-photon fluorophore and p-hydroxyaniline as a leaving-recognition domain. Both the probe and the fluorophore were investigated under one- and two-photon excitation modes. The fluorescence intensity of the probe was enhanced by ∼229-fold and ∼193-fold under one-photon and two-photon excitation, respectively, after reacting with HOCl. A maximal two-photon action cross-section of 50 GM was obtained under excitation at 810 nm. The probe exhibited high sensitivity with a detection limit of 42.3 nM, as well as high selectivity, low cytotoxicity, and good photostability. Two-photon microscopy (TPM) was conducted to visualize HOCl levels in living cells and tissues. The production of endogenous HOCl induced by lipopolysaccharide-mediated inflammation was successfully monitored with this probe.

MeSH terms

  • Animals
  • Fluorescence
  • Fluorescent Dyes / chemical synthesis
  • Fluorescent Dyes / chemistry*
  • Fluorescent Dyes / radiation effects
  • Fluorescent Dyes / toxicity
  • HeLa Cells
  • Humans
  • Hydrogen-Ion Concentration
  • Hypochlorous Acid / analysis*
  • Inflammation / chemically induced
  • Inflammation / metabolism*
  • Light
  • Limit of Detection
  • Lipopolysaccharides
  • Mice, Nude
  • Microscopy, Fluorescence / methods
  • Rats

Substances

  • Fluorescent Dyes
  • Lipopolysaccharides
  • Hypochlorous Acid