02834nas a2200253   4500008004100000022001400041245007900055210006900134260007100203300001400274490000700288520198600295653001402281653002002295653001302315653000802328653002602336653001802362100001902380700001902399700002702418700002202445856011302467       2013                        eng d  a0897-475600aLarge centimeter-sized macroporous ferritin gels as versatile nanoreactors0 aLarge centimetersized macroporous ferritin gels as versatile nan  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a4813-48190 v253 a<p>Organized assemblies of bionanoparticles such as ferritin provides templates that can be exploited for nanotechnological applications. Organization of ferritin into well-defined three-dimensional assemblies is challenging and has attracted considerable attention recently. We have synthesized, for the first time, large (centimeter-sized) self-standing macroporous scaffold monoliths from ferritin bionanoparticles, using dynamic templating of surfactant H-1 domains. These scaffolds comprise three-dimensionally connected strands of ferritin, organized as a porous gel with porosity similar to 55 mu m. The iron oxide inside the ferritin scaffold can be easily replaced with catalytically active monodisperse zerovalent transition metal nanoparticles using a very simple protocol. Since the ferritin is cross-linked in the scaffold, it is significantly robust with enhanced thermal stability and better tolerance toward several organic solvents in Comparison to the native ferritin bionanoparticle. In addition, the scaffold macropores facilitate substrate and reagent transport and hence the monoliths containing active Pd or iron oxide nanoparticles inside apo-ferritin bionanoparticles were used as a recyclable heterogeneous catalyst for the oxidation of 2,3,6-trimethyl phenol to 2,3,6-trimethyl-1,4-benzoquinone (precursor for Vitamin E synthesis) and for Suzuki-Miyaura cross-coupling reaction in both aqueous and organic solvents. The protein shell around the nanoparticles protects them from agglomeration, a phenomenon that otherwise plagues nanoparticles-based catalysis. The presence of macropores allow the ferritin scaffold to act as catalytic monolith for continuous flow reactions having rapid reaction rates, while offering a low pressure drop. Finally, the Pd@apo-ferritin scaffold was immobilized inside a steel cartridge and used for the continuous flow hydrogenation of alkenes to their corresponding alkanes for 15 cycles without any loss of activity.</p>10acatalysis10acontinuous flow10aferritin10agel10amacroporous materials10aSelf-assembly1 aKumari, Sushma1 aKulkarni, Amol1 aKumaraswamy, Guruswamy1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/large-centimeter-sized-macroporous-ferritin-gels-versatile-nanoreactors-0