Rising Stars in Analytical Chemistry Spring 2023

Congrats Rising Stars Spring 2023!

Meet the Rising Stars in Analytical Chemistry:

May 10th, 2023 1:00-2:30 pm EST

Tammi Van Neel

Localized cell-surface sampling using functionalized beads

Biography: Tammi was born in South Africa and grew up in sunny California. She completed her B.S. in chemistry at Florida State University in 2017. While there, she worked on developing an immunoassay for glucagon and glucagon-antigen detection using capillary electrophoresis under the guidance of Dr. Michael Roper. Currently, Tammi is a PhD candidate and HHMI Gilliam Fellow in the lab of Dr. Ashleigh Theberge at the University of Washington. Her research focuses on developing translational tools and methodologies for applications in biology. Specifically, she has developed a bead-based immunoassay for simultaneous cytokine detection and selective cell attachment as well as a user-friendly air sampling device for assessing environmental exposures in personal settings. Tammi has received several awards including a Diversity, Equity, and Inclusion Leadership Award from the UW Department of Chemistry (2022), Merck Research Award for Underrepresented Chemists of Color (2021), and the NOBCChE Analytical Chemistry Division Oral Presentation Award (2021). She has also given numerous research presentations and will have five first/co-first author publications by the end of her PhD which she will be defending Summer 2023. In addition to her research success, Tammi is an active member in the broader science community at UW and has served as a mentor to several students of color across the UW campus.

Abstract: Cellular communication using chemical signals is vital in many biological processes including immune response, cell behavior regulation, and homeostasis maintenance. Quantification of chemical signals from bulk fluids (i.e., cell culture supernatant samples) has been performed using a variety of traditional methods (e.g., well-plate-based immunoassay, mass spectrometry, liquid chromatography) and specialized approaches (e.g., microfluidic cell culture systems). However, they often lack key effector short-lived signaling molecules which are degraded, converted, or sequestered on timescales faster than analysis can be performed. This results in a diminished signal and provides an incomplete picture of the signaling microenvironment. We have created a customizable, dual-functionalized bead-based system that enables localized cell-surface sampling by simultaneously tethering beads to cell surfaces and capturing analytes as they are being secreted real-time by cells in live cell cultures. When our beads were tested in two conditions, one where a neutralizing factor was added and one without, our method captured similar analyte levels while a traditional method showed a significant decrease with the neutralizing factor. Therefore, our method may be useful in capturing short-lived signals that are important in modulating the immune response, cancer progression, and organ development.

Lamyaa Almehmadi

Enhanced Raman spectroscopy techniques for drug discovery, mRNA vaccine stability, and forensics

Biography: Lamyaa M. Almehmadi is a Ph.D candidate in Professor Igor K. Lednev’s laboratory at the University at Albany, State University of New York (SUNY Albany), originally from Jeddah, Saudi Arabia. She received her B.S. in Chemistry with emphasis on Chemical and M.S. degrees in Chemistry from SUNY Albany, completing her master’s thesis in only one year. Her master’s thesis work was published in Scientific Reports, one of the Nature family of journals, focusing on developing a label-free platform for medical diagnostics using surface-enhanced Raman spectroscopy. Lamyaa’s current research focuses on the use of Raman spectroscopy techniques for drug discovery, mRNA vaccine stability assessment, and forensics. She is an active member of the spectroscopy society, co-chairing sessions at conferences. She had been elected as the president of a local Society for Applied Spectroscopy chapter for two consecutive years. She has also participated in the general planning of an ACS virtual research symposium focused on younger chemists. Lamyaa has received several awards, including the prestigious Coblentz student award and an honorable mention for the National Graduate Women in Science Award. She taught General Chemistry twice as an instructor of record in the Chemistry Department at SUNY Albany and has co-organized educational outreach sessions. 

Abstract: Raman spectroscopy has proven to be an invaluable and remarkable analysis method for several applications. This talk will discuss the use of surface-enhanced Raman spectroscopy (SERS) in the context of drug discovery applications, specifically, using SERS as a sensitive and label-free technique for identifying hits, focusing on its potential to detect the binding between potential drugs and their targets. Additionally, I will share our work on using Deep-UV resonance Raman spectroscopy for monitoring mRNA vaccine degradation and the first use of stand-off Raman spectroscopy for detecting and identifying traces of body fluids. Overall, this presentation will highlight the unique capabilities and potential of Raman spectroscopy techniques in drug discovery, mRNA vaccine stability, and forensics.

Dr. Gabrielle Black

Investigating potential mammary gland carcinogens in California drinking water

Biography: Gabby Black received a B.S. from Dominican University of California in 2010 and a PhD in Agricultural and Environmental Chemistry from University of California Davis in 2019. The focus of her dissertation was the identification of persistent consumer product chemicals in sewage sludge and led a 120-household tap water study during a three-year postdoc. Using nontargeted analysis (NTA) paired with cell-based bioassays to measure estrogenic activity, Gabby investigated potential mammary gland carcinogens in drinking water throughout the state. Gabby is currently a postdoc at the U.S. Geological Survey working under the supervision of Dr. Michelle Hladik where she focuses on identifying novel pesticide-related contaminants in watersheds impacted by illegal cannabis grows, oil-derived compounds downgradient from subsurface oil spills, and characterizing dissolved organic matter using high resolution mass spectrometry. In the community, Gabby is an active participant in the BP4NTA organization working to standardize NTA and is the President of the Northern California SETAC chapter focusing on promoting student mentorship and exposure to STEM. Gabby was a recipient of the NSF Graduate Research Fellowship Program award in 2015, the SETAC/ACS ENVR Student Exchange award in 2017, and identified as a Distinguished Recent Alumni by Dominican University in 2016. 

Abstract: The California Breast Cancer Research Program identified four regions in CA as areas with disproportionally elevated breast cancer occurrence rates compared to the rest of the state. Drinking water has often been suspected, sometimes anecdotally, as a potential contributor to elevated cancer rates. This study used targeted and nontargeted chemical analysis with High Resolution Mass Spectrometry to identify potential contaminants of concern in these four breast cancer “hot spot” regions in addition to four regions with lower occurrence rates. Cell-based bioassays were used to help prioritize nontarget features that correlate with estrogenic activity, and therefore have a higher likelihood of interacting with endocrine systems related to breast cancer. A total of 270 kitchen tap and bottled water samples were collected for this study, representing four water source types: small and large surface water, groundwater, and mixed groundwater and large surface water, and two disinfection methods: chlorination and chloramination. Several chemicals were identified as either correlated to estrogenic activity or found in the “hot spot” regions at significantly higher levels in comparison to the others. Examples of these compounds include benzothiazole-2-sulfonic acid, a vulcanization accelerator, hexachlorobenzene, a probable human carcinogen, several PFAS and a suite of phthalate plasticizers.  


May 17th, 2021 1:00-2:00 pm EST

Genesis Barzallo

Exploring the complex chemical composition of plastic waste-derived alternative fuels

Biography: Genesis Barzallo is a Los Angeles native who earned her B.S. in Biochemistry from California State University, Los Angeles (CSULA). During her undergraduate studies, Genesis developed a passion for multidimensional separation science while conducting research on alternative fuels derived from plastic waste conversion using comprehensive two-dimensional gas chromatography (GCxGC) under the guidance of Dr. Petr Vozka. She successfully defended her undergraduate honors thesis, “Quantitative Analysis of Olefins in Petroleum Fractions by Two-Dimensional Gas Chromatography with Flame Ionization Detector,” and graduated with summa cum laude and departmental honors in Chemistry and Biochemistry. Genesis’ commitment to research led her to pursue a master’s degree in Chemistry at CSULA, and she has since had the privilege of presenting her research at various prestigious events, including the 2022 American Chemical Society (ACS) National Meeting in Chicago, IL and the 2022 Southern California Section of ACS Research Symposium at the Caltech, CA. She also received an honorary invitation to present at the 14th Multidimensional Chromatography Conference in Liège, Belgium and was the recipient of travel awards from both CSULA and ACS. In addition to her research, Genesis actively participates in various student outreach activities on campus, is the lab manager of C3AL, and aims to inspire more women to pursue careers in research.

Abstract: The accumulation of plastic waste has become a major environmental concern in recent years, as traditional waste management techniques like incineration and mechanical recycling have proven ineffective in dealing with the problem. As a result, innovative approaches, such as hydrothermal processing and pyrolysis, have emerged to convert plastic waste into valuable chemicals and alternative fuels. These fuels contain hundreds to thousands of compounds, and identifying their chemical composition is essential to optimize reaction conditions. My research focuses on the development of comprehensive two-dimensional gas chromatography (GCxGC) methods for such complex chemical mixtures. However, accurately quantifying olefins in these mixtures at high concentrations remains a challenge, as there are no established methods for this purpose. To address this gap, we developed a novel method for the characterization and quantitation of olefins in alternative fuels using GCxGC with a flame ionization detector. Our study presents a reliable method for accurately quantifying olefins in plastic waste-derived fuels, which could help assess the potential of plastic waste as an energy source.

Nathan Dominique

A chemical and analytical toolbox for N-heterocyclic carbene monolayers

Biography: Nathan earned his B.S. degree from the University of Georgia in 2019 where he majored in chemistry. Through undergraduate research programs with Prof. Gregory H. Robinson (University of Georgia, Athens) and Prof. David M. Jenkins (University of Tennessee, Knoxville), he developed an appreciation for creative scientific research which motivated him to pursue a PhD in Chemistry. Currently, Nathan is an Analytical Chemistry PhD candidate advised by Prof. Jon P. Camden at the University of Notre Dame. His research focuses on the development of N-heterocyclic carbene (NHC) monolayers for sensing applications. This research involves designing analytical methods that provide a window into NHC monolayer chemistry, including laser desorption/ionization mass spectrometry and electrochemical surface-enhanced Raman spectroscopy methods. Nathan has won several awards throughout graduate school, including the Berthiaume Institute Summer Fellowship and a Kaneb Center Teaching Award. He continues to promote a welcoming and diverse research environment through mentoring graduate and undergraduate students.

Abstract: Electrochemical biosensors have the potential to monitor therapeutics in vivo, which will enable personalized medicine once commercialized. However, gold-based biosensors rely on thiol monolayer chemistries that degrade in biofluids and during electrochemical cycling. To address these challenges, we designed a suite of functionalized N-heterocyclic carbene (NHC) monolayers on gold and an analytical toolbox to monitor NHC monolayer functionality and integrity. NHC monolayers expressing carboxylate and amine functional groups were prepared via a series of post-synthetic modifications. We monitored each step in the surface chemical reactions using laser-desorption ionization mass spectrometry (LDI-MS). The resulting mass spectra illustrate that NHC monolayers are easily tuned to prepare a suite of different functional groups useful for covalent immobilization of biomolecules. Then, to monitor the integrity of NHC monolayers in electrochemical biosensor conditions, we built an electrochemical surface-enhanced Raman spectroscopy (EC-SERS) instrument. EC-SERS spectra obtained during chronoamperometry experiments.

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