Collaborative Research: An Interdisciplinary Study of Chiral Molecular Adsorption on Mineral Surfaces

知识价值：晶体表面和水溶液之间的界面上发生的化学相互作用对非常广泛的科学和技术主题至关重要，包括腐蚀、多相催化剂、化学传感器和从油漆和胶水到溶剂和清洁剂的一系列基本日常产品。地球化学家特别关注矿物表面和水物种之间发生的反应--风化和土壤形成的核心相互作用、热液矿床沉积、pH缓冲、生物矿化和生物膜形成、影响水质的化学品的吸收和释放以及许多其他自然过程。在实验和理论最新进展的基础上，并利用卡内基研究所、史密森学会和约翰霍普金斯大学的资源，这项拟议的跨学科协作研究应用了多种技术组合来记录矿物和有机分子之间的手性(即手性)相互作用。这些相互作用对理解微生物生态学、生物矿化和生命的地球化学起源等不同主题具有深远的意义。此外，手性矿物-分子相互作用工程在许多前沿技术应用中具有巨大的潜力，包括手性药物的合成和提纯(每年1700亿美元的业务)、环境监测、行星生命检测和纳米制造。因此，这一建议为表征和预测有机分子与晶体表面之间的相互作用建立了新的实验和理论程序。在实验方面，DNA微阵列技术与飞行时间表面电离质谱分析相结合的新应用促进了多种不同分子物种在不同矿物表面吸附的组合研究。这些实验将首次详细记录哪些分子吸附在哪些表面上，但没有揭示这些相互作用的原子尺度方面。与实验相结合的补充理论建模将提供对松弛晶体表面上吸附几何结构的原子尺度的详细理解。因此，这项建议的最终目标是制定控制有机物种在矿物表面吸附的一般原则-这些原则将在科学和工业中得到广泛应用。更广泛的影响：所要求的资金将显著促进对有机分子和晶体之间相互作用的理解，同时开发实验和理论技术。特别是，利用微阵列技术的组合能力来研究矿物表面是一个令人振奋的新方向。这项研究特别适合本科生和研究生参与，其中四人在过去三年中已经为这些发展做出了贡献。公众传播也仍然是一个高度优先事项。这项工作在广播节目(包括NPR的地球和天空)、50多场公开讲座(包括可在网上观看的视频讲座和MSA总统演讲)、一般文章(包括《科学美国人》、《元素》和《地理时报》)以及美国国家科学院出版的《创世纪》(哈森2005)中都得到了强调。类似的外联活动将是拟议赠款的组成部分。总的来说，这些努力将促进对分子和晶体表面之间相互作用的科学理解，同时为矿物的新的实际工业应用打开大门。该项目由美国国家科学基金会和美国国家航空航天局天体生物学研究所联合支持，贡献了所需资金的50%以上。

Intellectual Merit: Chemical interactions occurring at interfaces between crystalline surfaces and aqueous solutions are crucial to an extraordinarily broad range of scientific and technological topics, including corrosion, heterogeneous catalysts, chemical sensors, and a host of essential everyday products from paints and glues to solvents and cleaners. Geochemists pay special attention to reactions that occur between mineral surfaces and aqueous species - interactions central to weathering and soil formation, hydrothermal ore deposition, pH buffering, biomineralization and biofilm formation, uptake and release of chemicals that affect water quality, and many other natural processes. Building on recent advances in experiment and theory, and harnessing resources of the Carnegie Institution, the Smithsonian Institution, and Johns Hopkins University, this proposed collaborative interdisciplinary research applies a combination of techniques to document chiral (i.e., handed) interactions between minerals and organic molecules. These interactions have profound relevance to understanding such diverse topics as microbial ecology, biomineralization, and the geochemical origins of life. Engineering of chiral mineralmolecule interactions, furthermore, has great potential in many forefront technological applications, including synthesis and purification of chiral pharmaceuticals (a $170 billion annual business), environmental monitoring, planetary life detection, and nanofabrication. Accordingly, this proposal establishes new experimental and theoretical procedures for the characterization and prediction of interactions between organic molecules and crystalline surfaces. On the experimental front, a novel application of DNA microarray technology combined with time-of-flight surface ionization mass spectrometric analysis facilitates the combinatorial investigation of adsorption by many different molecular species on various mineral surfaces. These experiments for the first time will document in detail which molecules adsorb to which surfaces, though without revealing atomic-scale aspects of those interactions. Complementary theoretical modeling integrated with experiments will provide detailed atomic-scale understanding of adsorption geometries on a relaxed crystalline surface. The ultimate objective of this proposal is thus to develop general principles governing the adsorption of organic species on mineral surfaces - principles that will have broad application to science and industry.Broader Impact: The requested funding will significantly advance understanding of interactions between organic molecules and crystals while developing experimental and theoretical techniques. In particular, exploiting the combinatorial power of microarray technology for the study of mineral surface represents an exciting new direction. This research is especially well suited for participation by undergraduate and graduate students, four of whom have already contributed to these developments during the past 3 years. Public dissemination also remains a high priority. The work has been highlighted on radio programs (including NPR's Earth & Sky), in more than 50 public lectures (including web-available videotaped lectures and the MSA Presidential Address), in general articles (including Scientific American, Elements, and Geotimes), and in the book Genesis published by the National Academy of Sciences (Hazen 2005). Similar outreach activities will be an integral part of the proposed grant. Collectively, these efforts will advance scientific understanding of interactions between molecules and crystalline surfaces, while opening the door to new practical industrial applications for minerals.This project is being supported jointly by NSF and NASA Astrobiology Institute, which is contributing over 50% of the requested funds.