The presence of gold bound to the polymer surface was confirmed by energy dispersive X-ray (EDX) analysis for the gold-bound polymers (referred to here as poly-1-Au and poly-2-Au) (Fig ). Further characterization by X-ray photoelectron spectroscopy (XPS) provided insight into the nature of the bound gold, which included Au 3+ and Au (0) species (Fig. and Fig. ). Based on the peak position of the Au (0) species, it can be inferred that Au clusters with a size of about 5 -10 atoms formed on the polymer surface . This remarkable result suggests that the polysulfide sorbents are not merely ligands for gold salts, but also redox active sorbents that bind and reduce gold. XPS also revealed the presence of sulfate, which could result from oxidation of the sorbents by the leach solution. These results are consistent with the dual role of poly-1 and poly-2 in both quenching the oxidants in the leach solution and binding gold.