DNA hydrogel as a template for synthesis of ultrasmall gold nanoparticles for catalytic applications.

DNA cross-linked hydrogel was used as a matrix for synthesis of gold nanoparticles. DNA possesses a strong affinity to transition metals such as gold, which allows for the concentration of Au precursor inside a hydrogel. Further reduction of HAuCl4 inside DNA hydrogel yields well dispersed, non-aggregated spherical Au nanoparticles of 2-3 nm size. The average size of these Au nanoparticles synthesized in DNA hydrogel is the smallest reported so far for in-gel metal nanoparticles synthesis. DNA hybrid hydrogel containing gold nanoparticles showed high catalytic activity in the hydrogenation reaction of nitrophenol to aminophenol. The proposed soft hybrid material is promising as environmentally friendly and sustainable material for catalytic applications.

Extraction of Noble and Rare-Earth Metals from Aqueous Solutions by DNA Cross-Linked Hydrogels.

Invited for this month's cover is the group of Prof. Shizuaki Murata and Dr. Anatoly Zinchenko from Nagoya University and the group of Prof. Vladimir Sergeyev from Moscow State University. The cover picture shows the accumulation of noble and rare-earth metals by DNA cross-linked hydrogel. Read the full text of the article on page 619 ff..

Extraction of Noble and Rare-Earth Metals from Aqueous Solutions by DNA Cross-Linked Hydrogels.

Treasure trove: A method for the extraction of noble and rare-earth metals by a DNA cross-linked hydrogel, based on high DNA affinity to these elements, is described. The hydrogel is promising in applications for metal accumulation and recycling.

Thiol-mediated anchoring of silver cations to DNA for construction of nanofibers on DNA scaffold.

The formation of metal-containing Ag-mercaptoethanol (-Ag-S(R)-)(n) complexes on DNA chain scaffold was studied by UV spectroscopy, zeta potential measurement, and fluorescence and transmission electron microscopies. Experimental results made clear the mechanism of DNA mineralization and compaction, according to which intercalation of silver cations into DNA scaffold and further formation of (-Ag-S(R)-)(n) oligomeric complexes on DNA induce efficient DNA chain compaction by terminal Ag(+) cations. By transmission electron microscopy the formation of fiber-like DNA-templated nanostructures was observed. DNA-Ag-thiol complexes are promising for DNA-templated engineering of hybrid 1D nanostructures with adjustable chemical functionalities by choosing appropriate thiol ligand.