XAS and XPS examination of the Au–S nanostructures produced via the reduction of aqueous gold(III) by sulfide ions

A Single-Use, In Vitro Biosensor for the Detection of T-Tau Protein, A Biomarker of Neuro-Degenerative Disorders, in PBS and Human Serum Using Differential Pulse Voltammetry (DPV)

“…This showed that the immobilization procedure was effective. The XPS results were in agreement with those reported by others [25,26,27,28]. Therefore, the anti-T-Tau bonded biosensor was ready for T-Tau antigen detection.…”

Submicrometer intermediates in the citrate synthesis of gold nanoparticles: New insights into the nucleation and crystal growth mechanisms

“…The scheme is believed to be applicable to other systems, making allowance for their special mechanisms. Particularly, we found that sulfide ions used in high enough concentrations for reduction of Au(III) suppress the fusion and growth of Au and Au 2 S clusters [17,43], stabilizing the quasi-liquid structures. In addition to mechanistic implementation, such quasi-liquid species can be applied instead of shaped nanoparticles for the preparation of, for example, nanostructured composite materials; such studies are now in progress in our laboratory.…”

Gold and silver nanoparticles surface functionalized with rhenium carbonyl complexes

“…These values are clearly different to the binding energies of the parent thiol [60]. The absence of S 2p peaks compatible with sulfide (S 2À ) ions confirms that no metal sulfide is present on the nanoparticle surfaces [67]. It is important to note the significant presence of the Na 1s peak in the XPS spectra that it is explained by the presence of anionic (eCOO À ) groups and justifies the nanoparticle solubility in water.…”

“…The lower binding energy peak can be assigned to aliphatic carbon atoms of 3-MPA capping molecules [68]. The S 2p region shows a signal that can be resolved in two peaks at 163.3, 162.0 eV for NaMP-Au and 164.6, 163.3 eV for NaMP-Ag (Supplementary Image 3), respectively, that correspond to the contributions of the 2p 3/2 and 2p 1/2 levels as would be expected for sulfur atoms in the thiolato form bonded to metal surface nanoparticles [67]. These values are clearly different to the binding energies of the parent thiol [60].…”

“…8, are typical of metallic silver [43]. The absence of signals from Au(I) and Ag(I) indicates that there is no metal sulfide on the nanoparticle surface [66,67].…”