ИСТИНА

DNA is well known as a good biomolecular template in synthesis of various metal nanoparticles. Application of DNA hydrogel represents an almost unexplored yet attractive strategy for construction of three-dimensional architectures of inorganic nanomaterials. DNA possesses a strong affinity to transition metals such as gold, which allows for the concentration of Au precursor inside a hydrogel. Au(III) coordinates with DNA bases and forms stable complexes. In our study a DNA crosslinked hydrogel, which efficiently absorbs Au(III), was used as a ‘reactor’ for in-gel synthesis of gold nanoparticles. Chemical reduction of HAuCl4 absorbed by the DNA hydrogel proceeds inside the hydrogel volume and yields well-dispersed non-aggregated spherical gold nanoparticles with a narrow size distribution. The average diameter of the nanoparticles varies from 2 to 5 nm on changing the pH during the reduction. The average size of these gold nanoparticles synthesized in DNA hydrogel is the smallest reported so far for in-gel metal nanoparticles synthesis.The distribution was obtained by measuring around 500 nanoparticles in two independently prepared hybrid hydrogel.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.