Synthesis, characterization and chemical oxidation of 5-(N-pyrrolyl)pentanethiol protected gold nanoparticles

5-(N-pyrrolyl)pentanethiol modified monolayer protected gold clusters (PPT-MPCs) have been synthesized and characterized by FT-IR, 1H-NMR, UV–vis spectra, Transmission electron microscopy (TEM), elemental analysis, XPS, cyclic voltammetry, and TGA. PPT-MPCs have been successfully cross-linked by chemical oxidation of the pyrrole units that confined to the surface of gold nanoparticles in the solution as well as in the form of monolayer. In comparison with as-prepared PPT-MPCs, oxidized PPT-MPCs from solution shows different mass loss behavior and electrical conductivity. The oxidation PPT-MPCs monolayer performed in the LB trough results in a red shift of surface plasmon absorption (∼10 nm) by comparing with that of the PPT-MPCs monolayer.