All Hydroxyl-Thiol-Protected Gold Nanoclusters with Near-Neutral Surface Charge

J Phys Chem Lett. 2021 Oct 14;12(40):9882-9887. doi: 10.1021/acs.jpclett.1c02989. Epub 2021 Oct 5.

Abstract

Hydrophilic gold nanoclusters (Au NCs) whose physical and chemical properties are not susceptible to large changes in pH are greatly desired for diverse applications. Here, we design Au NCs protected by a hydroxyl-thiol ligand (e.g., 1-thioglycerol (TG)) with a molecular formula of Au34(TG)22 as a proof-of-concept for a Au NC model with near-neutral surface charge. Unlike hydrophilic thiols with charged functional groups (e.g., carboxylate-thiol) that are usually used for hydrophilic Au NCs, this type of Au NCs is protected by hydroxyl-thiols, which are less susceptible to the prevailing pH conditions as the hydroxyl group is less acidic than water. More interestingly, the resulting Au NCs also possess pH-independent fluorescence intensity, making them suitable for applications under strong acidic conditions, which are currently not available in the reported hydrophilic Au NCs.

MeSH terms

  • Fluorescence
  • Gold / chemistry*
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions
  • Hydroxides / chemistry*
  • Metal Nanoparticles / chemistry*
  • Sulfhydryl Compounds / chemistry*
  • Surface Properties

Substances

  • Hydroxides
  • Sulfhydryl Compounds
  • Gold
  • hydroxide ion