chemistry

Polymer-based mixed conductors for applications in bioelectronics

Date: 
Friday, March 25, 2022 - 4:00pm to 5:00pm
Location: 
CP-114
Type of Event (for grouping events):

Jonathan Rivnay

Department of Biomedical Engineering and Simpson Querrey Institute

Northwestern University, Evanston, IL

Rivnay Group

 

 

 

Abstract: Direct measurement and stimulation of ionic, biomolecular, cellular, and tissue-scale activity is a staple of bioelectronic diagnosis and/or therapy. Such bi-directional interfacing can be enhanced by a unique set of properties imparted by organic electronic materials. These materials, based on conjugated polymers, can be adapted for use in biological settings and show significant molecular-level interaction with their local environment, readily swell, and provide soft, seamless mechanical matching with tissue. At the same time, their swelling and mixed conduction allows for enhanced ionic-electronic coupling for transduction of biosignals. Structure-transport properties allow us to better understand and design these active materials, providing further insight into the role of molecular design and processing on ionic and electronic transport, charging phenomena, and stability for the development of high-performance devices. Such properties stress the importance of bulk transport processes and serve to enable new capabilities in bioelectronics. In this talk I will discuss the design of new organic mixed conductors and future design rules for performance and stability. I will demonstrate how such materials properties relax design constraints and enable new device concepts and unique form factors, allowing for flexible amplification systems for electrophysiological recordings, and electroactive scaffolds to modulate tissue state and/or cell fate. New materials design continues to fill critical need gaps for challenging problems in bio-electronic interfacing.

 

Faculty Host: Dr. John Anthony

47th Annual Naff Symposium

Date: 
Friday, April 1, 2022 - 8:00am to 5:00pm
Location: 
WT Young Library Auditorium
Tags/Keywords:
Type of Event (for grouping events):

Innovation in Molecular Neuroscience

Schedule of Events - April 1, 2022

8:00am

Registration and Continental Breakfast
WT Young Library Gallery

8:50am

Welcome - TBD

9:00am

Dr. Erin Calipari
"A novel mechanism for hormonal regulation of reward circuits in the brain contributes to addiction vulnerability in females"

10:00am

Break
WT Young Library Gallery

10:30am

Dr. Tim Harris
"High capacity electrophysiology: How we got here and where we can go"

11:30am

Lunch & Break

1:00pm

Dr. Elizabeth Hillman
"Understanding the brain with high-speed 3D imaging of cell structure, function and identity"

2:00pm

Break & Poster Session Set-Up
WT Young Library Gallery; Jacobs Science Building, Atrium

2:30pm

Dr. Baljit Khakh
"Cells that tile your brain: Astrocyte roles in neural circuits"

3:30 - 5:00pm

Poster Session
Jacobs Science Building, Atrium

 

Speakers

Dr. Erin Calipari

Vanderbilt University

Dr. Calipari received her PhD in Neuroscience in 2013 in the laboratory of Dr. Sara Jones at Wake Forest University School of Medicine where she studied how self-administered drugs altered dopaminergic function to drive addictive behaviors. She then went on to complete her postdoctoral training with Dr. Eric Nestler at Icahn School of Medicine at Mount Sinai, where she used circuit probing techniques to understand the temporally specific neural signals that underlie motivation and reward learning. She is currently an Assistant Professor at Vanderbilt University in the Department of Pharmacology. Her independent work seeks to characterize and modulate the precise circuits in the brain that underlie both adaptive and maladaptive processes in reward, motivation, and associative learning.

Group Page

Dr. Tim Harris

Johns Hopkins University

Timothy Harris is a research professor in the Department of Biomedical Engineering. He leads the Applied Physics and Instrumentation Group at the HHMI Janelia Research Campus, and is the originator of the project that produced the Neuropixels Si probe for extracellular recording in animals, mostly mice, and rats. He shares his time between Janelia and Johns Hopkins and is working on projects to enable recording 10-20,000 neurons in rodents and 30-50,000 neurons in non-human primates, as well as stimulate with high resolution.

He received a BS in Chemistry at California Polytechnical State University, San Luis Obispo, and a PhD in Analytical Chemistry at Purdue University.

Group Page

Dr. Elizabeth Hillman

Columbia University

Elizabeth Hillman is professor of biomedical engineering and radiology at Columbia University and a member of the Mortimer B. Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Science at Columbia. Hillman received her undergraduate degree in physics and Ph.D. in medical physics and bioengineering at University College London and completed post-doctoral training at Massachusetts General Hospital/Harvard Medical School. In 2006, Hillman moved to Columbia University, founding the Laboratory for Functional Optical Imaging. Hillman’s research program focuses on the development and application of optical imaging and microscopy technologies to capture functional dynamics in the living brain. Most recently, she developed swept confocally aligned planar excitation (SCAPE) microscopy, a technique capable of very high speed volumetric imaging of neural activity in behaving organisms such as adult and larval Drosophila, zebrafish, C. elegans and the rodent brain. Hillman’s research program also includes exploring the interrelation between neural activity and blood flow in the brain, as the basis for signals detected by functional magnetic resonance imaging (fMRI). Hillman is a fellow of the Optical Society of America (OSA), the society of photo-optical instrumentation (SPIE) and the American Institute for Medical and Biological Engineering (AIMBE). She has received the OSA Adolf Lomb Medal for contributions to optics, as well as early career awards from the Wallace Coulter Foundation, National Science Foundation and Human Frontier Science Program.

Group Page

Dr. Baljit Khakh

University of California, Los Angeles

Baljit Khakh completed his Ph.D. at the University of Cambridge in the laboratory of Patrick PA Humphrey. He completed postdoctoral fellowships in the laboratory of Graeme Henderson at the University of Bristol, and then in the laboratory of Henry A. Lester and Norman Davidson at California Institute of Technology. In 2001, Khakh became Group Leader at the MRC Laboratory of Molecular Biology in Cambridge, and in 2006 he moved to the University of California, Los Angeles where he is Professor of Physiology and Neurobiology. Khakh’s work has been recognized, including with the NIH Director's Pioneer Award, the Paul G. Allen Distinguished Investigator Award, and the Outstanding Investigator Award (R35) from NINDS.

Group Page


2022 Naff Symposium Committee

Dr. Chris Richards - Chair

Jason DeRouchey (Chemistry)
Lance Johnson (Physiology)
Brandon Henderson (Marshall University)

 

 

Hall of Distinguished Alumni (William E. Seale)

On September 28, 2021, the University of Kentucky inducted 27 former students into the 2020 Hall of Distinguished Alumni. The alumni are being honored for their meaningful contributions to the Commonwealth, nation, and the world. The prestigious event, held every five years, was postponed last year due to pandemic restrictions.

Dr. Tanuja Koppal | Where Are They Now?

Biographical Sketch: 

CANCELLED - Macromolecular Receptors for Chemical Fingerprinting in Aqueous Media

Date: 
Friday, September 3, 2021 - 4:00pm to 5:00pm
Location: 
CP-114
Type of Event (for grouping events):

**CANCELLED**

Marco Bonizzoni

Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, AL, USA.
Alabama Water Institute, The University of Alabama, Tuscaloosa, AL, USA.

E-mail: marco.bonizzoni@ua.edu

Abstract: Artificial supramolecular receptors often rely on weak intermolecular interactions for their chemical recognition properties, so they may struggle to work in competitive media, chief among 

which are water solutions. However, aqueous media are very important in analytical, environmental, and biomedical applications, so it is valuable to adapt our supramolecular tools to them. With the right tools, even the weakest noncovalent interactions can be pressed into service in aqueous media. We have been using water-soluble polymers (e.g. dendrimers, hydrogels, conjugated polymers) as scaffolds to build multivalent supramolecular sensors that take advantage of the large number of interactions and of the preorganization of receptor sites afforded by such scaffolds, resulting in improved affinity in buffered aqueous solutions near neutral pH. We have successfully built systems for the detection of interesting guest families, including carboxylate anions, simple saccharides, heavy metal cations, and polycyclic aromatic hydrocarbons. These are examples of a general approach with two key advantages. On the one hand, installing known receptor chemistry on a polymer scaffold affords a modular approach to multivalency with minimal design and synthesis effort. This improves the apparent strength of weaker interactions and allows them to overcome desolvation costs in water. On the other hand, water-soluble macromolecular scaffolds impart solubility to water-incompatible receptor families.

This simple approach is particularly valuable when designing chemical fingerprinting systems (sometimes referred to as an “electronic nose” or “tongue”) that typically require many different receptors, each one poorly selective, and recovers selectivity from judicious interpretation of the ensemble response.

**CANCELLED**

Mass spectrometry method development for the discovery and characterization of secondary metabolites

Date: 
Friday, July 16, 2021 - 10:00am to 11:00am
Location: 
Zoom
Type of Event (for grouping events):

Abstract: Secondary metabolites are organic compounds produced by an organism for reasons other than growth and development. In plants, secondary metabolites generally act as defense agents produced to deter predators and inhibit other competitive species. For humans, these compounds can often have a beneficial effect and are pursued and utilized as natural pharmaceuticals. The development of sensitive, high-throughput analytical screening methods for plant derived metabolites is crucial for natural pharmaceutical product discovery and plant metabolomic profiling. Here, metabolomic profiling methods were developed using a microfluidic capillary zone electrophoresis device and evaluated against traditional separation approaches. An alkaloid screening assay was constructed to analyze transgenic mutant plant extracts for novel metabolites. Putatively identified novel features were detected, elucidated, and then isolated and purified for pharmaceutical evaluation. Additionally, methods for the analysis of polyphenolic plant-derived secondary metabolites, such as cannabinoids, were also developed and evaluated. In this case, the occurrence of cross-instrumental variation was addressed, given the tight legal restrictions regarding commercialization the products in question. Lastly, the microfluidic CZE-MS methods were further applied for both primary and secondary metabolite profiling in a DMPK assay. This assay was developed to inclusively monitor metabolic changes as a response to varying concentrations of a therapeutic in circulation. The metabolomic methods developed and evaluated in this work displayed high sensitivity, efficiency, and accuracy and can be utilized across a wide variety of applications.

Attend the seminar here. Password 618011.

Synthesis, Crystal Engineering, and Material Properties of Small-Molecule Organic Semiconductors

Date: 
Tuesday, July 27, 2021 - 11:00am to 12:00pm
Location: 
Zoom
Type of Event (for grouping events):

Abstract: Small-molecule organic materials are of increasing interest for electronic and photonic devices due to their solution processability and tunability, allowing devices to be fabricated at low temperature on flexible substrates and offering utility in specialized applications. This tunability is the result of functionalization through careful synthetic strategy to influence both material properties and solid-state arrangement, both crucial variables in device applications. Functionalization of a core molecule with various substituents allows the fine-tuning of optical and electronic properties, and functionalization with solubilizing groups allows some degree of control over the solid-state order, or crystal packing. These combinations of core chromophores with varying substituents are systematically evaluated to develop structure-function relationships that can be applied to numerous applications. In this work, heteroacenes are investigated for singlet fission and triplet harvesting, with known crystal engineering strategies applied to optimize crystal packing and maximize relevant solid-state interactions. Further, a class of antiaromatic compounds are investigated using the same approaches to build up structure-function relationships and provide insight into the properties of a relatively understudied core molecule.

Attend the seminar here.

Understanding and Controlling Electrochemistry for Electrolyzers and Batteries

Date: 
Wednesday, October 6, 2021 - 4:00pm to 5:00pm
Location: 
Zoom
Type of Event (for grouping events):

Professor Andrew Gewirth

The University of Illinois at Urbana-Champaign

Understanding and Controlling Electrochemistry for Electrolyzers and Batteries

Abstract:

This talk addresses the electrochemical reactivity associated with electrolyzers and batteries.  Relevant to electrolyzers we show that electrodeposition of CuAg or CuSn alloy films under suitable conditions yields high surface area catalysts for the active and selective electroreduction of CO2 to multi-carbon hydrocarbons and oxygenates.  Alloy films containing Sn exhibit greater efficiency for CO production relative to either Cu along or CuAg at low overpotentials.   In-situ Raman and electroanalysis studies suggest the origin of the high selectivity towards C2 products to be a combined effect of the diminished stabilization of the Cu2O overlayer and the optimal availability of the CO intermediate due to the Ag or Sn incorporated in the alloy.  Sn-containing films exhibit less Cu2O relative to either the Ag-containing or neat Cu films, likely due to the increased oxophilicity of the admixed Sn.  Incorporation of a polymer into the Cu electrodeposit leads to very active CO2 reduction electrocatalysis due to pH changes at the electrified interface.  Vibrational spectroscopy is used to evaluate the pH at the interface during electrolyzer operation.

Relevant to batteries, we discuss solid electrolytes (SEs) which have become a practical option for lithium ion and lithium metal batteries due to their improved safety over commercially available ionic liquids. The most promising of the SEs are the thiophosphates whose excellent ionic conductivities at room temperature approach those of commercially-utilized electrolytes. Hybrid solid-liquid electrolytes exhibit higher ionic conductivities than their bare solid electrolyte counterparts due to decreased grain boundary resistance, enhanced interfacial contact with electrodes, and decreased degradation at the interface. Spectroscopic and structural studies on these latter materials lead to new formulations and artificial SEI materials exhibiting advantageous properties.

Host: ECS UK chapter

Advances and challenges in understanding the electrocatalytic conversion of carbon dioxide to fuels

Date: 
Wednesday, September 8, 2021 - 10:00am to 11:00am
Location: 
Zoom - https://uky.zoom.us/j/83419323701?pwd=YUZuc25QVDJZemlDR3JiVHlZZURXdz09
Type of Event (for grouping events):

Professor Marc T. M. Koper

Leiden University, Netherlands

Advances and challenges in understanding the electrocatalytic conversion of carbon dioxide to fuels

Abstract:

The electrocatalytic reduction of carbon dioxide is a promising approach for storing (excess) renewable electricity as chemicalenergy in fuels. Here, I will discuss recent advances and challenges in the understanding of electrochemical CO2 reduction. I will summarize existing models for the initial activation of CO2 on the electrocatalyst and their importance for understanding selectivity. Carbon–carbon bond formation is also a key mechanistic step in CO2 electroreduction to high-density and high-value fuels. I will show that both the initial CO2 activation and C–C bond formation are influenced by an intricate interplay between surface structure (both on the nano- and on the mesoscale), electrolyte effects (pH, buffer strength, ion effects) and mass transport conditions. This complex interplay is currently still far from being completely understood.

Y.Y.Birdja, E.Perez-Gallent, M.C.Figueiredo, A.J.Göttle, F.Calle-Vallejo, M.T.M.Koper, Nature Energy 4 (2019) 732-745

Host: ECS UK chapter

Alysia Kohlbrand, Former UK Chemistry ChemCat President, Presses on to Graduate School in Chemistry during the Pandemic

Alysia Kohlbrand graduated from the University of Kentucky in 2019 with double majors in Chemistry and Neuroscience.

This interview is part of a series conducted by the department called, "UK Chemistry Alumni: Where Are They Now." This interview was coordinated by Dr. Arthur Cammers.

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