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Gold nanoparticles modified with thiol-terminated polystyrene (AuPS) were synthesized and applied to the colorimetric detection of perfluorooctanoic acid (PFOA). The color change of the AuPS solution from red to blue-purple upon addition of PFOA was easily confirmed by the naked eye. Using several acids and fluorinated compounds, the detection system was shown to be selective for PFOA and tridecafluoroheptanoic acid, which suggests that both a highly acidic carboxyl group and a fluorocarbon group are required for the color change. Transmission electron microscopy (TEM) suggested that the addition of PFOA caused detachment of the polystyrene layer from the surface of the gold nanoparticles, which resulted in interparticle aggregation.

We examined Aspergillus melleus protease (Amano protease P) and A. oryzae protease (Amano protease A) as catalysts for peptide bond formation via the kinetically controlled approach. As the coupling efficiency was only moderate, even with a good amino acid substrate as the carboxyl component, in acetonitrile as a solvent (with or without a small amount of added water) that we had mainly employed previously in α-chymotrypsin catalyzed couplings, other solvent systems were sought. In 1,1,1,3,3,3-hexafluoro-2-propanol-DMF (1:1) without added water, these Aspergillus proteases were found to remain active for a long period of time and to be utilizable for peptide synthesis when the carbamoylmethyl ester was employed as the acyl donor, though the coupling efficiencies were dependent rather largely on the combination of the amino acid residues at the coupling site. The superiority of the carbamoylmethyl ester to conventional esters, for example the methyl ester, was once again established. Furthermore, some segm...

Pyrroles substituted with long alkoxy groups are prepared by the reaction of iminodiacetic acid dimethyl ester and dimethyl oxalate and the subsequent alkylation. These pyrroles are good precursor molecules for the corresponding porphyrins, which are expected to form an ordered columnar mesophase and are able to co-ordinate to various metals.

New methods for functionalization of conductive poly(thiophenes) and poly(pyrroles) using fused aromatics or crown ethers are discussed.