RUI: Selenium-modified Electrodes: From Surface Reactivity to Biosensing Developments

在化学系化学测量和成像项目的支持下，巴纳德学院的Marisa Buzzeo教授和她的本科生团队研究了生物分子如何通过电子转移进行通信。可以通过电子转移获得的可调化学反应能力被自然利用在广泛的重要生化过程中。例如，光合作用和细胞呼吸作用依赖于电子在分子之间转移时的高度敏感性和选择性。Buzzeo小组正专注于必需微量元素硒的化学性质，这是一种天然抗氧化剂，以更深入地了解其在生物电子转移事件中的独特作用。他们的研究提供了关于这种元素的存在明显提供的反应性的基本信息。他们的工作发现也有可能导致对含硒和含硫分子的选择性传感，包括在临床环境中。该项目为巴纳德学院(Barnard College)的学生提供了多种跨学科研究机会，巴纳德学院是一所面向女性的文科本科院校，该项目通过以社区为基础的外展活动，让来自弱势背景的高中生和残疾人参与进来，促进未被充分代表的群体参与自然科学。其目的是让这两组人接触到否则看起来无法获得或无法获得的化学概念、应用和职业。准确测量氧化还原电位对于详细了解物种如何参与电子转移反应是必不可少的。含硫分子的电化学研究受到电极表面不必要的氧化和吸附的阻碍。新的电极材料已经被发现，在含硫的氧化还原活性分子的水溶液测量中显示出巨大的前景。研究表明，Se和Au之间的固有反应性产生了稳定和可重复的电极表面修饰，使得溶液基硫化物分析物的扩散电子转移变得容易。Buzzeo小组正致力于通过光谱和电化学技术的结合来表征硒修饰的电极。具体地说，他们正在测量生物硒和硫在硒修饰的金基质上的电化学行为，以获得基本的热力学参数，并利用优化的硒修饰表面开发一种便携式电化学生物传感器，用于检测胱氨酸，胱氨酸是已知的肾结石形成的罪魁祸首。在几个部门和机构的协作下，这项工作需要对表面和溶液形态进行表征，以建立对硒-金吸附层的分子水平的描述。通过对含硒和含硫的氨基酸、多肽和配体进行全面的电分析研究来评估传感能力。这些追求将产生有关硒-金表面反应性的基础知识，并将使测量生理上相关的氧化还原活性物种成为可能。这项工作为巴纳德大学的本科生提供了物理、无机、分析和生物化学的研究培训。此外，这项工作还包括让弱势背景的高中生和残疾人士参与的教育活动，以促进STEM工作队伍的更加多样化。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging program in the Division of Chemistry, Professor Marisa Buzzeo of Barnard College and her team of undergraduate research students study how biological molecules communicate via the transfer of electrons. The tunable chemical reactivity that is accessible by the transfer of electrons is harnessed by Nature in a wide range of important biochemical processes. Photosynthesis and cellular respiration, for example, rely on the exquisite sensitivity and selectivity with which electrons are transferred between molecules. The Buzzeo group is focusing on the chemical properties of the essential trace element selenium, a natural antioxidant, to gain a deeper understanding of its unique role in biological electron transfer events. Their studies provide fundamental information regarding the reactivity distinctly afforded by the presence of this element. Findings from their work also have the potential to result in selective sensing of selenium- and sulfur-containing molecules, including in clinical settings. This project provides multiple interdisciplinary research opportunities for students at Barnard College, a liberal arts undergraduate institution for women, and bolsters the participation of underrepresented groups in the physical sciences via community-based outreach activities involving high school students from disadvantaged backgrounds and individuals with disabilities. The aim is to expose both groups to chemical concepts, applications, and careers that would otherwise appear unattainable or inaccessible.The accurate measurement of redox potentials is imperative for detailed understanding of how species participate in electron-transfer reactions. Electrochemical studies of chalcogen-containing molecules are hindered by unwanted oxidation and adsorption on electrode surfaces. New electrode materials have been identified that demonstrate great promise for the aqueous measurement of chalcogen-containing redox-active molecules. It has been shown that the intrinsic reactivity between selenium and gold yields a stable and reproducible electrode surface modification that makes accessible diffusional electron transfer of solution-based chalcogen analytes. The Buzzeo group is working to characterize selenium-modified electrodes by a combination of spectroscopic and electrochemical techniques. Specifically, they are measuring the electrochemical behavior of biological selenium and sulfur species on selenium-modified gold substrates to obtain fundamental thermodynamic parameters, and using the optimized selenium-modified surfaces to develop a portable electrochemical biosensor for cystine, a known culprit in kidney stone formation. Aided by collaborations across several departments and institutions, the work entails characterization of both surface and solution speciation to build a molecular-level description of the selenium-gold adsorbate layer. Sensing capabilities are assessed through comprehensive electroanalytical study of selenium- and sulfur-containing amino acids, peptides, and ligands. Together these pursuits will yield fundamental knowledge about selenium-gold surface reactivity and will enable measurement of physiologically relevant redox-active species. The work offers Barnard undergraduates research training at the interface of physical, inorganic, analytical, and biological chemistry. Additionally, the work includes educational activities involving high school students from disadvantaged backgrounds and individuals with disabilities to promote a more diversified STEM workforce.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.