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

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.