Research Article

Nano Research

, Volume 1, Issue 4, pp 333-340

Open Access This content is freely available online to anyone, anywhere at any time.

Two distinct fluorescent quantum clusters of gold starting from metallic nanoparticles by pH-dependent ligand etching

  • Madathumpady Abubaker Habeeb MuhammedAffiliated withDST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras
  • , Subramani RameshAffiliated withDST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras
  • , Sudarson Sekhar SinhaAffiliated withUnit for Nanoscience and Technology, Department of Chemical, Biological and Macromolecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences
  • , Samir Kumar PalAffiliated withUnit for Nanoscience and Technology, Department of Chemical, Biological and Macromolecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences
  • , Thalappil PradeepAffiliated withDST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras Email author 

Abstract

Two fluorescent quantum clusters of gold, namely Au25 and Au8, have been synthesized from mercaptosuccinic acid-protected gold nanoparticles of 4–5 nm core diameter by etching with excess glutathione. While etching at pH ∼3 yielded Au25, that at pH 7–8 yielded Au8. This is the first report of the synthesis of two quantum clusters starting from a single precursor. This simple method makes it possible to synthesize well-defined clusters in gram quantities. Since these clusters are highly fluorescent and are highly biocompatible due to their low metallic content, they can be used for diagnostic applications.

http://static-content.springer.com/image/art%3A10.1007%2Fs12274-008-8035-2/MediaObjects/12274_2008_8035_Fig1_HTML.jpg

Keywords

Gold cluster glutathione pH ligand etching fluorescence