Epitaxial Electrodeposition of Chiral Metal Oxide Films

手性金属氧化物薄膜的外延电沉积

• 批准号: 0504715
• 负责人: Jay Switzer
• 金额: --
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0504715&HistoricalAwards=false
• 关键词: Epitaxial; Electrodeposition; Chiral; Metal; Oxide

Many biomolecules are chiral- they can exist in one of two enantiomeric forms that only differ in that their structures are mirror images of each other. Because one enantiomer tends to by physiologically active while the other is inactive or even toxic, drug compounds are increasingly produced in an enantiomerically pure form using solution-phase homogeneous catalysts and enzymes. Chiral surfaces offer the possibility of developing heterogeneous enantiospecific catalysts that can more readily be separated from the products and reused. In addition, such surfaces might serve as electrochemical sensors for chiral molecules - perhaps even implantable chiral sensors that could be used to monitor drug levels in the body. In the proposed work, chiral surfaces of metal oxides such as CuO, AgO, Bi2O3, PbO2, Tl2O3, Y2O3, and In2O3 will be electrodeposited onto achiral surfaces such as single crystal Au and Cu using chiral molecules such as tartaric acid and amino acids to direct the chirality. Surfaces will be electrodeposited which lack mirror or glide plane symmetry. It is not necessary for the materials to crystallize in a chiral space group. The absolute configuration of the films will be determined by X-ray pole figure analysis, and the microstructure will be probed by electron and scanning probe microscopy. The concept of electrochemical biomineralization will be explored by depositing calcite in the presence of chiral agents by electrochemically generating base in a solution of calcium bicarbonate. The mechanism of chiral electrodeposition will be explored to determine whether the chiral molecules simply template the surface or imprint it. The mechanism will be probed by in situ techniques like scanning tunneling microscopy, vibrational spectroscopy, and electrochemical quartz microbalance experiments. Finally, the chiral oxide surfaces will be used to produce chiral electrochemical sensors. These sensors will be screened for the chiral recognition of simple chiral molecules such as tartaric and amino acids, in addition to more complex pharmaceutical drugs.Chirality is ubiquitous in Nature. Many biomolecules, such as pharmaceuticals and chemical warfare agents are chiral. They are non-superimposable mirror images of each other. One hand of the molecule can be an effective drug, while the other hand can be ineffective or even lethal. Thalidomide is an example- one hand is a sedative, while the other hand produces birth defects. In the proposed work, chiral metal oxides will be deposited by electrodeposition, a simple and inexpensive method. The chirality of the films will be controlled by the addition of chiral molecules such as tartaric acid and amino acids. The chiral films will be tested as sensors for simple chiral molecules and more complex pharmaceutical drugs. Students and postdoctoral associates will be provided with an interdisciplinary research environment in the Materials Research Center. The PI has a research group consisting of chemists, physicists, chemical engineers, and materials scientists. The students will also have the opportunity to work with the pharmaceutical company AstraZeneca Corporation on the development of chiral sensors. Undergraduate research is an important part of the project. Funding is provided each year for two undergraduate student researchers.

许多生物分子是手性的-它们可以以两种对映体形式之一存在，其不同之处在于它们的结构是彼此的镜像。 因为一种对映体倾向于生理活性，而另一种是无活性的或甚至有毒的，所以使用溶液相均相催化剂和酶越来越多地以对映体纯的形式生产药物化合物。 手性表面提供了开发多相对映体特异性催化剂的可能性，这些催化剂可以更容易地从产物中分离并重复使用。 此外，这种表面可能作为手性分子的电化学传感器-甚至可能是可植入的手性传感器，可用于监测体内的药物水平。 在本论文中，我们将利用手性分子如酒石酸和氨基酸来引导手性，将金属氧化物如CuO、AgO、Bi_2 O_3、PbO_2、Tl_2 O_3、Y_2 O_3和In_2 O_3的手性表面电沉积到非手性表面如单晶Au和Cu上。将对缺乏镜面或滑动面对称性的表面进行电沉积。材料不需要在手性空间群中结晶。薄膜的绝对配置将通过X-射线极图分析确定，并将通过电子和扫描探针显微镜探测微观结构。电化学生物矿化的概念将通过在手性试剂存在下通过在碳酸氢钙溶液中电化学产生碱来沉积方解石来探索。 将探讨手性电沉积的机理，以确定手性分子是否只是简单地模板表面或压印它。该机制将通过原位技术，如扫描隧道显微镜，振动光谱和电化学石英微天平实验进行探测。最后，手性氧化物表面将用于制备手性电化学传感器。这些传感器将筛选简单的手性分子，如酒石酸和氨基酸的手性识别，除了更复杂的药物。 许多生物分子，如药物和化学战剂是手性的。它们是彼此不可重叠的镜像。该分子的一只手可以是有效的药物，而另一只手可能无效甚至致命。 沙利度胺就是一个例子--一只手是镇静剂，而另一只手却会产生出生缺陷。 在这项工作中，手性金属氧化物的沉积将通过电沉积，一个简单而廉价的方法。通过添加手性分子如酒石酸和氨基酸来控制薄膜的手性。 手性薄膜将作为简单手性分子和更复杂药物的传感器进行测试。学生和博士后将在材料研究中心提供一个跨学科的研究环境。PI有一个由化学家、物理学家、化学工程师和材料科学家组成的研究小组。 学生还将有机会与制药公司阿斯利康公司合作开发手性传感器。本科生研究是该项目的重要组成部分。 每年为两名本科生研究人员提供资金。