Clusters of gold

Muhammed MAH, Pradeep T (2010) Luminescent quantum clusters of gold as bio-labels. In Demchenko AP (ed) Advanced Fluorescence Reporters in Chemistry and Biology II. Springer Ser Fluoresc 9 333-353... 

Abstract Quantum clusters of gold are materials with a core dimension in the subnanometer regime. They exhibit a totally different chemistry when compared with the metallic nanoparticles. In this chapter, we present this new family of materials. Various approaches used for the synthesis of both water and organic soluble clusters are described. After reviewing the various properties of these clusters with special reference to their luminescent properties, we look at their bio-labeling applications. We hope that this chapter initiates the reader into a new family of materials in the context of luminescence imaging and other purposes. 

Quantum clusters of gold can be synthesized in different ways. All the synthetic methods reported so far can be broadly classified into four categories. 

Habeeb Muhammed MA, Ramesh S, Sinha SS et al (2008) Two distinct fluorescent quantum clusters of gold starting from metallic nanoparticles by pH-dependent ligand etching. Nano Res 1 333-340... 

Habeeb Muhammed MA, Shaw AK, Pal SK et al (2008) Quantum clusters of gold exhibiting FRET. J Phys Chem C 112 14324-14330... 

Bimetallic clusters of gold were reviewed by Braunstein and Rose (6) in 1985, and Hall and Mingos (7) surveyed both homonuclear and hetero-nuclear gold clusters in the previous year. In addition, Steggerda et al. (8) reviewed the preparation and properties of gold clusters in 1982, Jones (9) has listed gold clusters studied by single-crystal X-ray diffraction up to mid... 

Figure 4.39. Immuuoelectron Microscopy. The opaque particles (150-A, or 15-nm, diameter) in this electron micrograph are clusters of gold atoms bound to antibody molecules. These membrane vesicles from the synapses of neurons contain a channel protein that is recognized by the specific antibody. [Courtesy of Dr. Peter Sargent.]...

The clusters of some elements have been at the center of the scientific interest, whereas those of others have not been so. Maybe the most studied element in this context is gold. However, here various theoretical approaches have problems in obtaining qualitatively the same results. Thus, clusters of gold atoms seem to be a topic just of its own the results depend very sensitively on the approach used in describing the interatomic interactions, and different theoretical approaches may lead to markedly different predictions. We shall, therefore, not discuss this element further here the interested reader may consult, e.g., 55,82. 

Figure 3 The HOMOs and LUMOs of the triangular cluster of gold...

A. M. Joshi, W. N. Delgass, K. T. Thomson, Analysis of O2 adsorption on binary-alloy clusters of gold Energetics and correlations, /. Phys. Chem. B 110 (2006) 23373. 

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