title: Layer-by-layer polypeptide macromolecular assemblies-mediated synthesis of mesoporous silica and gold nanoparticle/mesoporous silica tubular nanostructures.
abstract: A simple and versatile approach is proposed to use the LbL-assembled polypeptide macromolecular assemblies as mediating agents and templates for directed growth of gold nanoparticles and biomimetic silica mineralization, allowing the synthesis of polypeptide/silica and polypeptide/gold nanoparticle/silica composite materials, as well as mesoporous silica (meso-SiO2) and gold nanoparticle/mesoporous silica (Au NP/meso-SiO2). The formation of tubular nanostructures was demonstrated by silicification and growth of gold nanoparticles within macromolecular assemblies formed by poly(L-lysine) (PLL) and poly(L-glutamic acid) (PLGA) using polycarbonate membranes as templates. The experimental data revealed that the silicified macromolecular assemblies adopted mainly sheet/turn conformation. The as-prepared mesoporous silica materials possessed well-defined tubular structures with pore size and porosity depending on the size of sheet/turn aggregates, which is a function of the molecular weight of polypeptides. The directed growth of Au NP and subsequent silica mineralization in the macromolecular assembly resulted in Au NP/meso-SiO2 tubes with uniform nanoparticle size and the as-prepared materials exhibited promising catalytic activity toward the reduction of p-nitrophenol. This approach provides a facile and general method to synthesize organic-inorganic composite materials, oxide and metal-oxide nanomaterials with different compositions and structures.
authors.affiliation: Department of Chemical Engineering, National Cheng Kung University , No. 1, University Rd., Tainan, Taiwan 70101, Taiwan.
authors.forename: Jeng-Shiung
authors.initials: JS
authors.lastname: Jan
authors.forename: Tzu-Han
authors.initials: TH
authors.lastname: Chuang
authors.forename: Po-Jui
authors.initials: PJ
authors.lastname: Chen
authors.forename: Hsisheng
authors.initials: H
authors.lastname: Teng
mesh_terms: D006046:Gold / Q000737:chemistry*; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010455:Peptides; D006046:Gold; D012822:Silicon Dioxide