We herein report that hydrogels can be prepared from guanosine and boronic acids in the presence of K⁺ and Pb²⁺ ions. These supramolecular hydrogels are formed via G-quartet like self-assembly of guanosine and its boronate esters. The potential of this hydrogel construct in mimicking enzyme-like activity has been demonstrated for the first time. We have observed that the self-assembled structure present in K⁺ stabilized hydrogel binds to iron(III)-hemin and shows peroxidase activity, catalyzing oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H₂O₂. Furthermore, the conformation of the G-quartet assemblies in the hydrogel can be altered by varying the stabilizing cations K⁺ and Pb²⁺. This conformational switching has been used to devise a molecular logic gate for sensing of toxic Pb²⁺ ions.

中文翻译：

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从DNA结构启发的超分子水凝胶模拟过氧化物酶活性

我们在本文中报道可以在K ⁺和Pb ²⁺离子存在下由鸟苷和硼酸制备水凝胶。这些超分子水凝胶是通过G四联体形成的，如鸟苷及其硼酸酯的自组装。首次证明了这种水凝胶构建体在模仿酶样活性方面的潜力。我们已经观察到存在于K ⁺稳定水凝胶中的自组装结构与铁（III）-血红素结合并显示过氧化物酶活性，在H存在下催化3,3'，5,5'-四甲基联苯胺（TMB）的氧化₂ O ₂。此外，可以通过改变稳定阳离子K ⁺来改变水凝胶中G四元组组装体的构象和Pb ²⁺。这种构象转换已被用于设计用于感测有毒Pb ²⁺离子的分子逻辑门。