Seminars/Events

Chemistry Department Seminars

Chemistry Department Seminars will take place online until further notice. In order to attend a department seminar, please contact the chemistry department at chemistry@wwu.edu to request the Zoom meeting information.

The department strives to offer a diverse and vibrant seminar program. Each year leading researchers from outside the department, as well as faculty and graduate students from Western, present and discuss their cutting-edge research. This is an excellent opportunity for students, faculty, staff, and visitors to actively participate in the scientific community. In addition, many outside seminar speakers are recruiting graduate students for their respective programs and are eager to discuss their program. All are welcome and encouraged to attend! 

Photo Credit Roisin Cowan-Kuist, 2019

Spring Quarter 2021

Current Seminar Schedule 

Seminars will be hosted on Zoom throughout Winter Quarter 2021. If you are interested in attending a seminar, please email chemistry@wwu.edu to request the seminar zoom attendance information.

Seminars typically take place on Friday from 3:15-4:15pm

Seminar topics and titles will be posted as we receive additional information from speakers.

Recordings of select seminars will be available on the Chemistry Department Canvas page. If you wish to watch a previously recorded seminar please reach out to chemistry@wwu.edu

 

Spring Quarter 2021

April 2, 2021 - Julia Zhao

Professor, University of North Dakota

Nanoparticles for Bioanalytical and Energy-related Applications

Abstract: Luminescent nanomaterials have demonstrated great promise as optical probes in bioanalysis due to their unique optical properties and high surface-to-volume ratio. In comparison with traditional fluorescence labeling techniques that usually use fluorescent dye molecules to signal target bioconjugation and other biological interactions, the luminescent nanoparticle labeling method provides enhanced detectable signal and reproducibility. This advancement in luminescent techniques makes direct and rapid detection of trace amounts of biomolecules possible. In addition, nanoparticles have shown a great potential in energy-related applications. In this presentation, the synthesis, characterization, and applications of several nanomaterials will be reported, including graphene-based nanomaterials, quantum dots, and nanocatalysts.

 

April 9, 2021 - College to Career

WWU Chem Club

 

April 16, 2021 - Bozhi Tian 

Associate Professor, University of Chicago

Physical Biology at the Semiconductor-enabled Subcellular Interfaces

Abstract: Biointerface devices can probe fundamental biological dynamics and improve the lives of human beings. However, the direct application of traditional rigid electronics onto soft tissues or cells can cause signal transduction and biocompatibility issues, due to mechanical mismatch at the biointerfaces. One common mitigation strategy is the use of nanostructures or soft-hard composites to form more biocompatible interfaces with target cells or tissues. My group integrates nanoscience and soft matter physics with biophysics to study several semiconductor-based biointerfaces. In this talk, I will first pinpoint domains where semiconductor properties can be leveraged for biointerface studies, providing a sample of numbers in semiconductor-based biointerfaces. Next, I will present a few recent studies from our lab and highlight key bioelectrical mechanisms underlying the non-genetic optical modulation interfaces. In particular, I will present a biology-guided two-step design principle for establishing tight intra-, inter-, and extracellular silicon-based bioelectrical interfaces in which semiconductors and the biological targets have matched mechanical properties and efficient signal transduction. Research in my lab has revealed how the physicochemical outputs from the photothermal, photofaradic, and photocapacitive effects of nanostructured semiconductors can be identified, quantified, and utilized at semiconductor-based biointerfaces to modulate electrical activities in neurons, cardiomyocytes and bacterial cells. The non-genetic and free-standing materials-based methods have the potential to overcome the limitations of current metal electrode-based devices such as bulk and cell membrane disruption, and are not dependent on genetic modifications. Finally, I will discuss new tissue-like materials and other biological targets that could catalyze future advances.

 

April 23, 2021 - Leilei Tian

Associate Professor, Southern University of Science and Technology 

Hydrophobic Interaction: A Promising Driving Force for the Biomedical Applications of Nucleic Acids

Malignant tumors pose a major threat to human life and health. Achieving early diagnosis and treatment of tumors has always been an important topic of concern for the scientific community. The development of biocompatible nano-medicines that can sensitively respond to changes in the delivery environment has become a promising way to solve the problem. Thus, the tumor microenvironment and biomarkers, such as the reactive oxygen species (ROS), hypoxia, the acidity, the abnormally expressed proteins, the non-coding small RNAs, and some metabolites, have been selected as the essential targets. Compared with synthetic polymers, DNA is more biocompatible and shows good recognition and responsive capabilities to tumor microenvironments and biomarkers. Thus, functional nucleic acid has been widely used in biological analysis and cell sensing. However, the disadvantages of DNA, such as poor biological stability and low cell membrane permeability, have limited its further applications in cancer diagnosis and treatment.

The comprehensive understanding and proper use of supramolecular interactions have become critical for the development of functional materials, and so does the biomedical application of functional DNA. Hydrophobic interaction shows some unique properties, such as flexibility in application interest, minimal effect to DNA functionality, and the sensitivity to external stimuli. Accordingly, our group mainly exploits hydrophobic interaction to improve the biological availability of DNA and subsequently develop the DNA-based biomaterials in higher-order self-assembly, drug/gene-delivery system, and stimuli-responsive system. Herein, I will introduce our recent progress, mainly in (1) Utilizing the hydrophobic interaction of DNA itself, which comes from the accumulation of base-stacking forces, to develop novel drug delivery systems. (2) DNA is conjugated with hydrophobic dyes showing aggregation-sensitive optical properties, to develop stimuli-responsive materials for bio-sensing and therapeutics. (3) Novel biomedical materials are developed based on the self-assembly of DNA amphiphiles.

April 28, 2021 @ 2:00PM

Thesis Defense - Walker Marks

Title

"Demystifying Denitrification: Coordination Complexes Give Valuable Insight into the Reduction of Nitrogen Oxides"

Abstract

Increasing human population is driving the need to produce increasing amounts of food without the ability to dramatically increase farmland area. This is accomplished by the application of increasing amounts of nitrogen containing fertilizers. The nitrogen fertilizer use is causing imbalance in the natural nitrogen cycle via excessive amounts of oxidized nitrogen entering both the atmosphere and aquatic ecosystems, which are major contributors to global warming and environmental damage. This thesis will explore the functionalization of a dinuclear dinitrosyl iron complex which is capable of coupling nitrosyl to release nitric oxide. The activity of this system is explored through examination of mono-nuclear dinitrosyl complexes as well as modification of the secondary-sphere ligand interactions which allow control of nitrous oxide evolution from a dinuclear dinitrosyl complex. The complete denitrification of nitrate by divalent samarium in a “single pot” is presented, which represents one of few synthetic systems that are capable of such reactivity.

April 30, 2021 - Srikanth Singamaneni 

Professor, Washington University St. Louis

Abstract: Detection, imaging, and quantification of low abundant biomolecules within biological fluids, cells, and tissues is of fundamental importance but remains extremely challenging in biomedical research as well as clinical diagnostics. We have designed and synthesized an ultrabright fluorescent nanoconstruct, termed “plasmonic-fluor”, as an “add-on” bio-label to dramatically improve the signal-to-noise ratio of a wide variety of existing fluorescence bioassays without altering or complicating the conventional assay workflow or read-out devices. We demonstrate that these novel nanoconstructs can be readily utilized in a broad range of bioanalytical methods, including fluorophore-linked immunosorbent assays, multiplexed bead-based immunoassays, immuno-microarrays, flow cytometry, and immunocytochemistry, to attain more than 1000-fold improvement in the limit-of-detection and dynamic range. Building on this work, we demonstrate minimally-invasive and ultrasensitive quantification of target protein biomarkers in interstitial fluid through microneedle-assisted in vivo sampling and subsequent on-needle analysis. With the microneedle patch, we demonstrate minimally-invasive evaluation of cocaine vaccine efficiency and longitudinal monitoring of inflammatory biomarker levels in mice. In the second part of the talk, we describe the use of silk fibroin and metal-organic frameworks as protective coatings to stabilize antibodies bound to nanotransducers against thermal denaturation and loss of biorecognition. This biopreservation approach overcomes the poor stability of existing biosensors and takes them closer to real-world applications in resource-limited settings.

 

Bio: Dr. Singamaneni is the Lilyan & E. Lisle Hughes Professor in the Department of Mechanical Engineering and Materials Science at Washington University in St. Louis. He obtained his PhD in Polymer Materials Science and Engineering from Georgia Institute of Technology in 2009. His research group is involved in the design, synthesis and self-assembly of plasmonic nanostructures for various biomedical applications. He has co-authored more than 150 refereed articles (including 11 invited reviews) in archival journals, 9 book chapters, and a book (Scanning Probe Microscopy of Soft Matter: Fundamentals and Practices). He is a recipient of the NSF CAREER award, Dean’s Faculty Award for Innovation in Research, Translational New Investigator Award, DOD-Army and Materials Research Society Graduate Student GOLD Award.

 

May 7, 2021 - Shirin Faraji

Associate Professor, University of Groningen 

Title: Excited-state processes and quantum effects in complex environment 

Abstract:

Light-triggered processes, which are ubiquitous in nature and technology, are inherently quantum.  Phenomena such as photovoltaic effect, charge migration, and proton-coupled electron transfer require quantum mechanical description. Understanding and optimizing these processes is the key to novel technologies: molecular electronics, optogenetics, and clean energy devices. By simulating excited-state dynamics and modeling relevant spectra, computer simulations can help to translate experimental observations into molecular-level, to provide detailed insight into the primary photochemical reactions, and finally to facilitate the computer-aided design of new molecules and materials with customized properties matching specific applications. I will present examples of light-induced processes relevant for optogenetics,  molecular electronics, and solar cells. I will highlight the role of theory in developing mechanistic understanding of these important systems and outline the theoretical approaches used for this task with a particular emphasis on fundamental challenges in the field. Last but not least, PySurf will be introduced as an innovative Python based code framework. It is specifically designed for rapid prototyping and development tasks for data science applications in computational chemistry.

 

May 14, 2021 - Gang Chen

Assistant Professor, University of Central Florida 

 

Title: Towards Precise Control of Plasmonic Nanomaterials: From Synthetic Chemistry to Self-assembly

Abstract: The diversity of materials in structure and properties originates from the 3D arrangement of atoms through chemical bonds which allows atoms to form either large-scale crystals or small molecules. At the nanoscale, next to the molecular scale, aggregates of nanoparticles (NPs) are expected to have unique properties and applications if they can self-assemble like atoms. So far, many literatures have reported the self-assembly of NPs into periodic structures, called superlattices. However, molecular-like NP assemblies are rarely seen due to the absence of valence on their surfaces. In this talk, I will present our recent work on how to create colloidal analogues of atoms at nanoscale with valence, namely “artificial atoms”, so as to achieve “molecular-type” self-assemblies at nanoscale through the “direct bonding” between “artificial atoms”. More specifically, my talk will show our recent effort on: (1) synthesize NPs with homogeneity in both size and shape like atoms; (2) convert NPs into “artificial atoms” with chemically distinct surface areas that mimic hybridized atomic orbitals, such as sp, sp2, sp3, sp3d, and sp3d2; and (3) realize the molecularization of NPs and their “chemical reactions” to achieve diverse and complex nanostructures. The completion of this work results in: (1) new synthetic approaches and a better understanding of growth mechanism, beneficial to the future customized synthesis of NPs; (2) a better understanding of surface chemistry at nanoscale and developing new surface engineering techniques; (3) enrich the colloidal assembly technique and improve the complexity of colloidal metamaterials. It also provides many exciting opportunities for discovering new applications of nanomaterials in many interdisciplinary research fields.

Biography: Dr. Gang Chen is an Assistant Professor in Department of Chemistry at the University of Central Florida (UCF). Dr. Chen received his PhD in Physical Chemistry from the Chinese Academy of Sciences in 2008. He did his postdoc training at Nanyang Technological University, Singapore and the University of Chicago, focusing on the self-assembly of nanomaterials. He started his independent career at UCF since 2016. His long-term goal is to establish a highly active research program that designs unique, robust and widely applicable synthetic strategies across the molecular and nano scale, and that enable effective manufacturing and incorporation of nanomaterials into innovative diagnostics, therapeutic, catalytic, and energy conversion technologies.

May 18, 2021 @ 3:00PM

Thesis Defense - Briana Mulligan

Title:

Synthesis of rupestines C, D and K with studies toward rupestines B, J, L and M.

Abstract: 

Rupestines B-D and J-K belong to the family of naturally occurring guaipyridine alkaloids that can be isolated from the plant Artemisia rupestris. Inspiration for their synthesis stems from the previously synthesized guaipyridine alkaloid, cananodine, which has displayed potent in vitro cytotoxic effects against two types of hepatocellular carcinoma (HCC, liver cancer) cell lines. The unique structural moiety of these alkaloids is a fused pyridine ring and seven-membered carbocycle. The key step in the reported synthesis is an intramolecular Mizoroki-Heck cyclization for the assembly of the bicyclic system. Rupestines C, D and K have been synthesized and isolated as single diastereomers. The synthesis and isolation of rupestines B, J, L and M is currently in progress. 

May 21, 2021 - Catherine Murphy

Professor, University of Illinois at Urbana-Champaign 

Bonus! Dr. Murphy will have a Q&A with students and faculty before their talk.

May 28, 2021 - Chaoyang Yiang

Professor, University of South Dakota

 

June 4, 2021 - Scholarship and Awards Ceremony

 

WWU Chemistry Research Publications