Hybrid Materials for the Enzymatic Reduction of Carbon-Dioxide

酶是用于可持续的和无有机溶剂的化学转化的催化剂的选择，但是如果它们的环境没有被仔细控制，则仍然存在缺乏稳定性和酶活性损失的问题。在这个项目中，新的生物催化材料将被合成和表征。其目的是创造出具有高二氧化碳还原活性的强效含酶材料。薄的水凝胶层（nm至mm厚）将在固体载体上生长，用于支持的酶催化。水凝胶膜将通过二肽两亲物在平坦表面和多孔材料内部的表面引发有序化而形成水凝胶基质。酶的稳定性和活性将从三个方面得到改善。(1)将比较来自嗜温菌（生活在温和环境中的生物体）和嗜极菌（在极端条件下生长的生物体）的酶的活性和稳定性。(2)酶将固定在肽水凝胶基质中，该基质模拟生物有机体中的细胞外基质。肽凝胶将是一种表面结合的凝胶，具有开放的（99%体积的水）结构，非常适合固定酶，同时仍然允许小分子扩散进出。此外，凝胶将提供局部控制的pH环境并防止蛋白质解折叠。(3)为了进一步提高稳定性并产生坚固的材料，水凝胶将在高度多孔的无机氧化物膜的内表面区域上自组装。最终产品将是一种集成的催化材料，可将二氧化碳还原为甲酸和其他有用的有机原料分子。

Enzymes are the catalysts of choice for sustainable and organic solvent free chemical transformations, but there remain issues with the lack of stability and loss of activity of enzymes if their environment is not carefully controlled. In this project new bio-catalytic materials will be synthesised and characterised. The aim is to create robust enzyme-containing materials that have high activity for the reduction of carbon dioxide. Thin hydrogel layers (nm to mm thick) will be grown on solid supports for applications in supported enzyme catalysis. The hydrogel films will be created by the surface initiated ordering of di-peptide amphiphiles into hydrogel matrices both on flat surfaces and inside porous materials. Enzyme stability and activity will be improved in three ways. (1) The activity and stability of enzymes from both mesophiles (organisms that live in moderate environments) and extremophiles (organisms that thrive under extreme conditions) will be compared. (2) The enzyme will be immobilised in a peptide hydrogel matrix that mimics the extracellular matrix in biological organisms. The peptide gel will be a surface bound gel that has an open (99% water by volume) structure ideal for immobilising enzymes while still allowing the diffusion of small molecules in and out. In addition the gel will provide a locally controlled pH environment and prevent unfolding of the protein. (3) To improve stability still further and create a robust material, the hydrogel will be self-assembled on the internal surface area of a highly porous inorganic oxide film. The final product will be an integrated catalytic material that reduces carbon dioxide to formic acid and other useful organic feedstock molecules.