Article Title

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

Authors

Madathumpady Abubaker Habeeb Muhammed, DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India
Subramani Ramesh, DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India
Sudarson Sekhar Sinha, Unit for Nanoscience and Technology, Department of Chemical, Biological and Macromolecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
Samir Kumar Pal, Unit for Nanoscience and Technology, Department of Chemical, Biological and Macromolecular Sciences, Satyendra Nath Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098, India
Thalappil Pradeep, DST Unit on Nanoscience (DST UNS), Department of Chemistry and Sophisticated Analytical Instrument Facility, Indian Institute of Technology Madras, Chennai 600 036, India

Keywords

Gold cluster, glutathione, pH, ligand etching, fl uorescence

Abstract

Two fl uorescent 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 fi rst 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 fl uorescent and are highly biocompatible due to their low metallic content, they can be used for diagnostic applications.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-008-8035-2

Publisher

Tsinghua University Press

Recommended Citation

Madathumpady Abubaker Habeeb Muhammed,Subramani Ramesh,Sudarson Sekhar Sinha,Samir Kumar Pal,Thalappil Pradeep, Two distinct fluorescent quantum clusters of gold starting from metallic nanoparticles by pH-dependent ligand etching. NanoRes.2008, 1: 333-340