Cerium oxide particles as functional haloperoxidase mimics to combat biofouling

氧化铈颗粒作为功能性卤过氧化物酶模拟物来对抗生物污垢

• 批准号: 405861793
• 负责人: Professor Dr. Thomas Ternes
• 金额: --
• 依托单位: Bundesanstalt für Gewässerkunde (BfG)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/405861793?language=en
• 关键词: Cerium; oxide; particles; functional; haloperoxidase

Surfaces in aqueous habitats are usually colonized by microorganisms. A textbook example is the settlement of bacteria, unicellular organisms, algae or shells on ships or port facilities. A current strategy to reduce this so-called biofouling is the addition biocides in paints. Microorganisms enter into synergistic communities in the formation of biofilms and co-ordinate film formation through signaling via signaling molecules ("quorum sensing"). A defense mechanism of marine organisms is based on disrupting cell-to-cell communication of epibionts by enzymatic formation of halogenated - and thus ineffective - signaling molecules. The proposed project uses CeO2-x nanoparticle (NP) enzyme (haloperoxidase) mimics, which - analogously to natural haloperoxidases - catalyze the oxidation of ubiquitous halides by hydrogen peroxide (generated in daylight). The resulting hypohalous acid (HOX) intermediates react with organic substrates in follow-up to form the halogenated signal molecules. The metal oxide particles can be immobilized on surfaces as a constituent of paints and resins without losing their effect. The catalytic halogenation of a halogenated signal compound has been demonstrated in laboratory experiments. The project aims to achieve the following objectives by pooling the expertise of both project partners:1. Unraveling the sequence of the halogenation reactions: Does the reaction proceed via short-lived HOBr/HOCl intermediates, or are other reactive intermediates involved? Which halogenated signaling compounds are formed in natural waters (i.e., in the field)? What is the stability of these halogenated primary intermediates and in what concentrations are they formed? Which other compounds are formed?2. The catalytic activity of CeO2-x NP in halogenation reactions is determined by defects. By increasing the defect concentration in different solid state solution series (e.g., CeO2-M2O3, (M = La, Y, Bi, etc.) the activity should be improved.3. Alternative halogenation catalysts: Besides the halogenation properties of CeO2-x and its substituted variants, the halogenation activity of Ce perovskites (BaCe1-xO3-y etc.), Ce-substituted silica compounds (Ce-TUD-1), delafossite-type composites (CuCrO2-CeO2), or Mn oxides will be tested.4. The use of CeO2-x NP (and possible alternatives) in antifouling applications requires the availability in sufficient amounts. The synthesis must be scaled up to the kg scale.5. Analytical examination and optimization of the resistance of the coatings and their surface properties: The particles should be integrated into films or coatings for use under application oriented conditions. The surface properties must be optimized, the bacterial and algae growth on the films and the leaching of the particles (environmental compatibility) and the released products will be determined.

含水生境的表面通常被微生物定植。典型的例子是细菌、单细胞生物、藻类或贝壳在船舶或港口设施上的沉降。目前减少这种所谓的生物污染的策略是在油漆中添加杀菌剂。微生物在形成生物膜的过程中进入协同群落，并通过信号分子（“群体感应”）发出信号来协调膜的形成。海洋生物的一种防御机制是通过酶促形成卤化（因此无效）信号分子来破坏表观生物的细胞间通讯。拟议的项目使用CeO2-x纳米颗粒（NP）酶（卤素过氧化物酶）模拟物，类似于天然卤素过氧化物酶，催化过氧化氢氧化无处不在的卤化物（在日光下生成）。所得到的次卤酸（HOX）中间体随后与有机底物反应形成卤化信号分子。金属氧化物颗粒可以作为油漆和树脂的组成部分固定在表面上而不会失去其效果。卤化信号化合物的催化卤化已在实验室实验中得到证实。该项目旨在通过汇集两个项目伙伴的专门知识来实现以下目标：揭开卤化反应的顺序：反应是通过短寿命的HOBr/HOCl中间体进行的，还是涉及其他活性中间体？哪些卤化信号化合物是在自然水域（即田间）形成的？这些卤化初级中间体的稳定性如何？它们形成的浓度是多少？还会形成哪些化合物？CeO2-x NP在卤化反应中的催化活性由缺陷决定。在不同的固溶体系列(如CeO2-M2O3， （M = La， Y， Bi等）中增加缺陷浓度可以提高活性。替代卤化催化剂：除了CeO2-x及其取代变体的卤化性能外，还将测试Ce钙钛矿（BaCe1-xO3-y等），Ce取代二氧化硅化合物（Ce- tud1）， delafocite型复合材料（CuCrO2-CeO2）或Mn氧化物的卤化活性。在防污应用中使用CeO2-x NP（和可能的替代品）需要足够数量的可用性。这种合成必须按比例放大到公斤级。涂层阻力及其表面性能的分析检测和优化：颗粒应集成到薄膜或涂层中，以便在面向应用的条件下使用。必须优化表面性能，确定细菌和藻类在膜上的生长以及颗粒的浸出（环境相容性）和释放产物。