CAREER: CAS: Developing Gas Bubbles as a New Tool for Surface-Active Agent Analysis

在韦恩州立大学化学系化学测量和成像项目的支持下，罗龙教授和他的团队正在努力开发一种强大的新方法，用于识别和定量分析一类重要的化合物。具体来说，他们的目标是被称为表面活性剂的分子，表面活性剂在许多家用清洁剂和工业产品和工艺中广泛用作乳化剂、洗涤剂、织物柔软剂和润湿剂。天然存在的表面活性剂，如糖脂、脂肽、脂蛋白、脂肪酸、中性脂和磷脂，对生物系统的功能也是必不可少的。目前的表面活性剂分析方法不能检测特定的产物（选择性）和低浓度（灵敏度）。罗教授和他的团队正在开发新的电化学方法来解决这些挑战。他们还致力于应用现场检测多氟烷基物质（PFAS）的工具，这是一组新兴的表面活性剂，是饮用水中令人关注的污染物。这项工作的综合教育目标是通过在公共场所进行科学表演，提高不同年龄、教育水平、社会经济和文化背景的人们对STEM的认识、兴趣和职业准备；为初高中学生开发STEM接触项目；并在韦恩州立大学建立和管理电化学学会的学生分会。值得注意的是，该团队将通过在密歇根州最大的两个家庭景点五大湖十字奥特莱斯购物中心和底特律动物园组织和表演一场科学表演，向公众宣传科学与日常生活的相关性。选择性和灵敏度有限一直是表面活性剂分析中存在的问题。为了解决这些问题，Luo团队正在利用气泡-表面活性剂相互作用建立一种选择性和灵敏度高的检测方法，并结合快速高效的预富集。具体来说，表面活性剂独特的两亲性会影响电化学气泡成核，进而影响用于表面活性剂定量的电化学信号。采用模拟海雾气溶胶富集的方法对表面活性剂进行预浓缩。这些功能结合在一个便携式设备中，以解决饮用水中PFAS现场检测的未满足需求，解决美国环境保护署将PFAS定量确定为国家优先事项所引起的担忧。该教育计划的更广泛影响包括提高公众对科学技术的兴趣，促进初高中学生参与分析化学活动，提高本科生和研究生对电化学的兴趣。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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 Long Luo and his group at Wayne State University are working to develop a powerful new approach for the identification and quantitative analysis of an important class of chemical compounds. Specifically, they are targeting molecules known as surfactants, which are widely used as emulsifiers, detergents, fabric softeners, and wetting agents in many household cleaners and industrial products and processes. Naturally occurring surfactants such as glycolipids, lipopeptides, lipoproteins, fatty acids, neutral lipids, and phospholipids are also essential to the functioning of biological systems. Current methods for surfactant analysis do not detect specific products (selectivity) and low concentrations (sensitivity). Professor Luo and his group are developing new electrochemical approaches to address these challenges. They are also working on applying the tools for on-site detection of polyfluoroalkyl substances (PFAS), a group of emerging surfactants that are contaminants of concern in drinking water. The integrated educational aims of this work seek to increase STEM awareness, interest, and career preparedness across a range of ages, educational levels, and socioeconomic and cultural backgrounds by performing science shows at public locations; developing STEM exposure programs for middle and high school students; and establishing and running a student chapter of the Electrochemical Society at Wayne State University. Notably, the team will reach out to the public about the relevance of science in everyday life by organizing and performing a science show at the Great Lakes Crossing Outlets Mall and Detroit Zoo, the two largest family attractions in Michigan.Limited selectivity and sensitivity have been a long-standing problem in surfactant analysis. To address these issues, the Luo group is using the gas bubble-surfactant interaction to establish a selective and sensitive detection method coupled with rapid and efficient preconcentration. Specifically, the unique amphiphilic characteristics of surfactants affect electrochemical gas bubble nucleation, which in turn impacts an electrochemical signal used for the quantification of surfactants. An approach mimicking sea-spray aerosol enrichment is used to preconcentrate the surfactants. These features are being combined in a portable device to address the unmet need for on-site detection of PFAS in drinking water, addressing concerns arising from U.S. Environmental Protection Agency identification of PFAS quantitation as a national priority. Broader impacts of the educational plan include increasing public interest in science and technology, promoting middle and high school students’ engagement in analytical chemistry activities, and boosting undergraduate and graduate students’ interest in electrochemistry.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.