A polypeptide-mediated synthesis of green fluorescent gold nanoclusters for Fe3+ sensing and bioimaging

J Colloid Interface Sci. 2017 Nov 15:506:386-392. doi: 10.1016/j.jcis.2017.07.062. Epub 2017 Jul 18.

Abstract

In this paper, growth hormone releasing peptide-6 (GHRP-6) is a bioactive polypeptide and acts as the reducing agent and capping ligand for synthesis of bright green fluorescent gold nanoclusters (GHRP-6-Au NCs) by a simple and environmental-friendly aqueous method, with the assistance of NaBr as the fluorescent sensitizer. The obtained GHRP-6-Au NCs had high fluorescent quantum yield (10.7%), and the fluorescence was strongly quenched by the existence of trace Fe3+. Thus, a new and highly sensitive sensor for the assay of Fe3+ was constructed based on the analyte-induced fluorescent quenching mechanism. The sensor had a low detection limit of 1.4µM (S/N=3) and a wide linear range of 2-1000µM. Besides, GHRP-6-Au NCs exhibited low cytotoxicity and high biocompatibility for cell imaging.

Keywords: Bioimaging; Fluorescent gold nanoclusters; Fluorescent sensor; Growth hormone releasing peptide-6.

MeSH terms

  • Cell Survival
  • Chromaffin Cells / chemistry
  • Fluorescent Dyes / chemistry*
  • Gold / chemistry*
  • HeLa Cells
  • Humans
  • Iron / analysis*
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Oligopeptides / chemistry*
  • Optical Imaging
  • Particle Size
  • Peptides / chemistry*
  • Sensitivity and Specificity
  • Spectrometry, Fluorescence
  • Surface Properties

Substances

  • Fluorescent Dyes
  • Oligopeptides
  • Peptides
  • growth hormone releasing hexapeptide
  • Gold
  • Iron