Gas–liquid interface discharge at atmospheric pressure above HAuCl4 solutions containing no protective agents generates triangular and hexagonal nanoplates and nanorods of gold. Experimental results under several different conditions indicate that the plates and rods rapidly grow on the surface of the solution. In contrast, the spherical nanoparticles slowly grow in the solution.

The process of laser-induced electropolymerization of aniline was studied by in situ surface-enhanced Raman scattering (SERS) spectroscopy and cyclic voltammetry (CV). Formation of p-coupled aniline oligomers was confirmed at an electrode potential below the oxidation potential of aniline, and the oligomers were found to be the source compound for photo-induced electropolymerization.

No abstract

Anion-selective detection is demonstrated for sulfate ion in aqueous solutions by using two-photon excited fluorescence of gold nanoparticles (AuNPs) modified with a thiourea-based anion receptor, bis[2-(3-(4-nitrophenyl)thioureido)ethyl]-disulfide. The fluorescent intensity increased with the change of the sulfate concentration in the solution from 10 -4 to 10 -3 M. In comparison with an unadsorbed receptor molecule in bulk acetonitrile solution, the molecule on AuNPs in water showed improved affinity for sulfate ion. The controllability of the hydrophobicity around receptor molecules on AuNPs is considered a dominant contributing factor for improved sulfate affinity. This unique feature of the surface enables us to detect anionic species in an aqueous phase where a dye-type indicator has poor sensitivity.