Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
Graduate School of Engineering, Nagoya University, Nagoya 464-8601, Japan.
ACS Appl Bio Mater. 2021 Feb 15;4(2):1823-1832. doi: 10.1021/acsabm.0c01533. Epub 2021 Jan 13.
DNA-chitosan (DNA-CS) hydrogels were prepared on the basis of interpolyelectrolyte complexes (IPEC) in a co-assembled regime by charging of the polysaccharide in a DNA solution. In contrast to poorly controlled coacervates formed upon mixing of DNA and CS solutions, stable DNA-CS IPEC hydrogels are formed at near-stoichiometric ratios of DNA and chitosan ionogenic groups. Structure, stability, and ion absorption properties of such hydrogels depended strongly on the ratio between cationic (CS) and anionic (DNA) counterparts in hydrogels. Abundant amino- and nitrogen-containing aromatic groups of co-assembled DNA and CS make their hydrogel an efficient, multitarget absorbent toward metal ions. Such strong affinity of both DNA and CS to Au cation was used to entrap Au ions into the DNA-CS hydrogels. Subsequent reduction of Au ion inside hydrogels resulted in the formation of ∼2-3 nm size Au nanoparticles on DNA-CS scaffolds. Metallized hydrogels demonstrated catalytic activity in reduction of various nitroaromatics that depended on the ratio between CS and DNA in the hydrogel.
DNA-壳聚糖（DNA-CS）水凝胶是通过在 DNA 溶液中带电荷使多糖发生电荷作用，在共组装状态下基于聚电解质复合物（IPEC）制备的。与 DNA 和 CS 溶液混合时形成的控制不佳的凝聚物不同，在 DNA 和壳聚糖离子基团的近化学计量比下形成稳定的 DNA-CS IPEC 水凝胶。这些水凝胶的结构、稳定性和离子吸收性能强烈依赖于水凝胶中阳离子（CS）和阴离子（DNA）对应物之间的比例。共组装的 DNA 和 CS 中丰富的氨基和含氮芳族基团使其水凝胶成为金属离子的高效多目标吸收剂。DNA 和 CS 对 Au 阳离子的这种强亲和力被用于将 Au 离子捕获到 DNA-CS 水凝胶中。随后，Au 离子在水凝胶内的还原导致在 DNA-CS 支架上形成约 2-3nm 大小的 Au 纳米粒子。金属化水凝胶在还原各种取决于水凝胶中 CS 和 DNA 比例的硝基芳烃方面表现出催化活性。
