Using a Macroporous Silver Shell to Coat Sulfonic Acid Group-Functionalized Silica Spheres and Their Applications in Catalysis and Surface-Enhanced Raman Scattering

In this paper, novel organic sulfonic acid group-functionalized silica spheres (SiO₂–SO₃H) were chosen as a template for fabricating core–shell SiO₂–SO₃H@Ag composite spheres by the seed-mediated growth method. The SiO₂–SO₃H spheres could be obtained easily by oxidation of the thiol group-terminated silica spheres (SiO₂–SH) with H₂O₂. Due to the presence of sulfonic acid groups, the [Ag­(NH₃)₂]⁺ ions were captured on the surface of the silica spheres, followed by in-site reduction to silver nanoseeds for further growth of the silver shell. By this strategy, the complete silver shell could be obtained, and the surface morphologies and structures of the silver shell could be controlled by adjusting the number of sulfonic acid groups on the silica spheres. A large number of sulfonic acid groups on the SiO₂–SO₃H spheres favored the formation of the macroporous silver shell, which was unique and exhibited good catalytic performance and a high surface-enhanced Raman scattering (SERS) enhancement ability

DNA-Compatible Cyclization Reaction to Access 1,3,4-Oxadiazoles and 1,2,4-Triazoles

DNA-encoded chemical library (DECL) technology is a commonly employed screening platform in both the pharmaceutical industry and academia. To expand the chemical space of DECLs, new and robust DNA-compatible reactions are sought after. In particular, DNA-compatible cyclization reactions are highly valued, as these reactions tend to be atom economical and thus may provide lead- and drug-like molecules. Herein, we report two new methodologies employing DNA-conjugated thiosemicarbazides as a common precursor, yielding highly substituted 1,3,4-oxadiazoles and 1,2,4-triazoles. These two novel DNA-compatible reactions feature a high conversion efficiency and broad substrate scope under mild conditions that do not observably degrade DNA