Swain Home

Greg Swain

We thank you for your interest in our research group at Michigan State University. We encourage you to explore this website to learn more about our interdisciplinary research and the students who are engaged in the projects.

Google Scholar: http://scholar.google.com/citations?user=WI4v_OoAAAAJ&hl=en

ResearchGate:https://www.researchgate.net/profile/Greg_Swain/info/?ev=prf_info

ResearcherID: B-302302010   http://www.researcherid.com/rid/B-3023-2010

ORCID: http://orcid.org/0000-0001-6498-8351

Twitter: https://twitter.com/MSUdiamond

 

MSU Affiliations:

Director, Summer REU Program in Cross-Disciplinary Research in Sustainable Chemistry and Chemical Processes (2014 - present)

Graduate Program Director, Neuroscience Program (2017-present)

Coordinator - Responsible Conduct of Research and Scholarly Activities, The Graduate School (2019-present)

Department of Chemical Engineering and Materials Science (Adjunct)

MSU Fraunhofer - Center for Coatings and Diamond Technologies

 

International Affiliations:

Fulbright Scholar, Escuela Politécnica Nacional - Ecuador (2019-2020)

Guest Visiting Professor, Keio University - Japan (2018-2019)

Fulbright Specialist - Czech Republic (2018)

Visiting Professor, Domaine Universitaire, Grenoble, France (summer 2001) 

Special Visiting Researcher (CAPES), Universidade Federal de São Carlos (Brazil), 2013-2016

 

Service:

Academic Advancement Network Leadership Fellow, MSU (2018-2019)

At-Large Member MSU Steering Committee (2017-2019)

At-Large Member MSU Faculty Senate (2017-2019)

At-Large Member MSU University Council (2017-2019)

Graduate Program Director, Neuroscience (2017-present)

ACS Committee on Professional Training, Member (2015-present)

Editor, Electroanalysis (Wiley), 2019-present

Guest Editor, Special Issue - "Nanocarbon Electrochemistry and Electroanalysis", Electroanalysis (Wiley), print date Jan 2016

Guest Editor, Special Issue - "Electrochemical Properties and Applications of Advanced Carbon Materials", Electrochimica Acta (Elsevier), print data Jan. 2016

Associate Editor, Critical Reviews in Analytical Chemistry, 2014-present

Advisory Board, Advanced Engineering Materials, 2014-present

Editorial Board, Diamond and Related Materials (Elsevier), 2006-2015

Editor-in-Chief, Diamond and Related Materials, 2011-2014

Editor, Diamond and Related Materials, 2009-2011


We welcome the incoming graduate students in 2018-19! The following are research projects available to interested students:

1. Preparation and testing of electrochemical sensors for nitric oxide and peroxynitrite, and application of these in a first-generation exhaled breath analyzer for respiratory disease diagnosis and management. These molecules are biomarkers of inflammation. Project will also involve measurements of these biomarkers in exhaled breath and exhaled breath condensate collected from patients with lung cancer. The project is collaborative with physicians in the College of Medicine.

2. Preparation and testing of ink-jet printed (carbon nanotubes and metal oxide powders) electrodes and their application in situ to monitor chronic wound healing. The long-term goal of this project is to use these inexpensive and small sensors to electrochemically measure biomarkers of wound healing (O2, pH, pyocyanin, uric acid) directly in wound fluid as part of a smart bandage. We also seek to learn more about fundamental wound healing processes and how these processes might be impaired in diseases such as diabetes. In this phase of the work, the sensors would be used to measure these biomarkers in artificial wounds introduced into a new diabetic mouse model. The project is collaborative with faculty in the Department of Microbiology and Molecular Genetics, and the College of Veterinary Medicine. 

3. Advanced carbon electrode materials are being developed to address key material problems in energy conversion and storage devices. Specifically, (i) a core-shell approach is be used to prepare boron-doped ultrananocrystalline diamond-coated powders to be used as a dimensionally-stable electrocatalyst support in PEM fuel cells, (ii) the same core-shell approach is being used to prepare metal-impregnated diamond-coated powders for application in electrocatalysis and (iii) high surface area, hybrid sp2/sp3 powders are being prepared for potential application in electrochemical double layer capacitors. The student will learn about chemical vapor deposition of diamond, various material characterization techniques, electrochemistry, and fuel cells and capacitors.

4. Fundamental research is being conducted to learn how the surface chemical modification of boron-doped diamond and nitrogen-incorporated tetrahedral amorphous carbon thin-film electrodes affects molecular adsorption, capacitance and electron-transfer kinetics of soluble redox probes in aqueous electrolyte solutions and and room temperature ionic liquids. The goal is to better understand factors that control the mechanism and kinetics of electrochemical reactions at these two novel carbon electrode materials. The student will learn about the chemical and physical vapor deposition of diamond and tetrahedral amorphous carbon, electrochemistry and spectroelectrochemistry.

5. In vitro electrochemical methods are being used to investigate neurosignaling processes at peripheral blood vessel surfaces and in the large and small intestine. Obesity-linked hypertension is often a complication for overweight individuals. Blood vessel tone is neurogenically controlled, in part, by sympathetic nerves that release norepinephrine and ATP (vasoconstrictors). It turns out that neurogenic control of arteries and veins is differentially regulated so a novel aspect of the work is the focus on both vessel types. A key issue to understand  is how signaling by these two mediators might be altered in obesity. Obesity-linked dysmotility also is often a complication. Content transits the gut by a process call peristalsis. Key neurosignaling molecules that affect this process are serotonin, nitric oxide and ATP. Students working on this project will apply diamond and carbon fiber microelectrodes (norepinephrine, serotonin) and microsized electrochemical sensors (NO and ATP) to study the release, action and clearance of these molecules in tissues isolated from mice, rats and or guinea pigs. The student would work on only one of the two projects and will learn about neuroanalytical chemistry, animal handling, tissue isolation and neuropharmacology. The project is collaborative with faculty in the Department of Pharmacology and Toxicology.


Research Synopsis

Research in our group is interdisciplinary and spans several fields: physical and analytical electrochemistry, carbon materials, corrosion science and neuroscience. We conduct fundamental research with advanced carbon materials to address key problems and technological needs in energy, health and the environment. Our core science lies in the preparation, processing and application of diamond and diamond-like carbons. We seek to considerably improve the ability to prepare and control the material properties of single and polycrystalline diamond, and nitrogen-incorporated tetrahedral amorphous carbon, and to explore frontier applications where the unique material properties are essential for performance.

The following descriptions provide an overview of some of the ongoing and new research projects in the group.

Amperometric Sensors and Biosensors for Health and the Environment

We are making use of nanostructured carbon materials and chemical functionalization strategies to develop a novel array of amperometric sensors and biosensors for use in human health. It is anticipated that the results derived from this research will provide several new and simple sensors that can be applied for important biomedical measurements in complex physiological samples.

The following sensors and biosensors are being developed for different applications:

1. Nitric oxide (NO) - This is an important enteric inhibitory neurosignaling molecule in the gastrointestinal tract. We are using this sensor in vitro to study how NO-mediated neuromuscular signaling is altered in obesity.

2. Peroxynitrite (PON) - This is an important marker of inflammation. We are using this sensor in vitro to probe for the presence of inflammation in the gut wall in obesity.

3. ATP - This is an important vasoconstricting neurotransmitter released from  sympathetic nerves that innervate blood vessels. It is also an enteric inhibitory neurotransmitter in the gut. We are using this biosensor in vitro to study how purinergic signaling in the vasculature and gut  is altered in obesity.

The NO and PON sensors are also part of a noninvasive analyzer being developed for exhaled breath and breath condensate. The goal of this project is to detect trace levels of these biomarkers of inflammation in exhaled breath. The innovative sensor-based technology could provide  on-site and point-of-care detection of these exhaled  biomarkers that are relevant in the management of asthma, cystic fibrosis, cancer and other respiratory diseases. This project is collaborative with faculty in the Departments of Medicine and the Lung Transplant Program. [Current funding = NIH and Clinical and Translational Sciences Institute, MSU]

Smart Bandages

An array of sensors is being developed using ink-jet printing technology for application in a “smart bandage”. The sensor system will report on the status of wound healing by measuring oxygen levels, pH, uric acid and toxins produced by infectious bacteria. The sensor array will also incorporate an electrode for electrogenerating oxidants to inactivate infectious bacteria, thus lessening the need for antibiotics. This project is collaborative with faculty in the Departments of Physiology, and Microbiology and Molecular Genetics, Small Animal Clinical Sciences (College of Veterinary Medicine, MSU) and EPFL (Switzerland).

 

Neuroelectrochemical Measurements in the Peripheral Vasculature and Gastrointestinal Tract

Neuroeffector transmission mechanisms differ depending on the target tissue. Abnormalities in signaling are associated with various diseases including hypertension and gastrointestinal disorders (e.g., IBS). We use diamond and carbon fiber microelectrodes along with in vitro electrochemical methods to investigate neuroeffector signaling in peripheral tissues. These measurements are useful for probing dynamic changes in concentration of an electroactive analyte in response to a stimulus. They also provide insight on the local neuropharmacology. Specifically, we are using these analytical methods to better understand the dysregulation that develops in obesity-associated (i) hypertension and (ii) gut dysmotility. Nearly 70% of American adults are either overweight or obese. Being obese puts one at a higher risk for diseases such as heart disease, stroke, high blood pressure, diabetes and more. Inexpensive conducting diamond is an enabling electrode material for these measurements because of its superior response sensitivity, reproducibility and stability in the complex tissue environment.

The target signaling molecules are (i) norepinephrine and ATP released from sympathetic nerves supplying arteries and or veins, (ii) serotonin released from enterochromaffin cells in the intestinal mucosa and (iii) nitric oxide and ATP released from inhibitory motor neurons in the gut. Tissues from animal models as well as humans are being used in the research. Immunohistochemical and pharmacological approaches, analytical separation methods and in vitro electrochemical methods are being employed to better understand these obesity-linked disorders. The projects are  collaborative with faculty in the Departments of Pharmacology and Toxicology. [Current funding = NIH].

Electrochemical Studies of Diamond and Tetrahedral Amorphous Carbon Thin-Film Electrodes - Comparisons in Aqueous Electrolytes and Room Temperature Ionic Liquids

We are investigating the interfacial structure, capacitance-potential profiles and the electron-transfer kinetics of soluble mediators in room temperature ionic liquids (RTILs). RTILs are emerging as a new class of “conducting” liquid with many important uses in electrochemistry. RTILs are composed of purely ions in the liquid state with no solvent. They generally have low volatility, high solubilizing power, good electrical and ionic conductivity, and are electrochemically stable (i.e., wide potential window).

It is well established that the surface cleanliness, microstructure and chemistry  affect electron-transfer kinetics at carbon electrodes. The heterogeneous electron-transfer rate constants for some redox systems are more strongly influenced by these variables in aqueous electrolyte solutions than are others. It is unclear if these variables affect electron-transfer kinetics in RTILs in the same manner. We are using conventional voltammetric measurements, digital simulations, electrochemical impedance spectroscopy and scanning electrochemical microscopy to study various redox systems at boron-doped diamond, tetrahedral amorphous carbon, glassy carbon and graphene electrodes. Bulk electrodes and thin films are being studied as are powderous (nanostructured) forms of the carbons. Various material characterization tools are being used to characterize the morphology, microstructure and surface chemistry of the electrodes including SEM/TEM, electrical measurements, contact angle measurements, XPS, XRD and Raman microprobe imaging. The goal of this work is to learn more about electron-transfer reactions in RTILs at different carbon electrodes and to correlate the physical, chemical and electronic properties of the electrodes with the heterogeneous electron-transfer reaction kinetics. [Current funding = Army Research Office].

Inorganic Coatings for Corrosion Prevention

A wide variety of materials are used in aerospace applications including light weight aluminum alloys, carbon fiber-epoxy composites, titanium alloys and steels. These materials, particularly the metals, are deployed with a multilayer coating system that provides corrosion protection. A typical coating system consists of a conversion coating, a primer and top coat. Understanding how to integrate these coatings in ways that minimize galvanic corrosion, pitting corrosion, and the resulting corrosion fatigue, is of paramount importance.

There are three primary goals driving the research: (i) replacement of the toxic Cr(VI)-containing coatings currently in use with more environmentally-friendly, non-chromate inorganic coatings (conversion coatings and primers), (ii) development of tetrahedral amorphous carbon (ta-C) coatings for contacting metal parts that offer both wear and corrosion resistance and (iii) understanding the degradation mechanisms of carbon fiber-epoxy composites when galvanically coupled. Students are studying and optimizing key processing parameters including (i) the method of application, (ii) substrate preparation (roughness, microstructure and chemistry), (iii) coating composition and structure, and (iv) post processing of the coating (aging and heat treatment).

Greater scientific insight regarding the fundamentals of corrosion and coating degradation during different accelerated degradation testing scenarios will lead to new materials, advanced coating systems, improved corrosion-prevention strategies, and thus better overall aerospace material performance. [Current funding = Office of Naval Research and Honeywell through the Department of Energy].

Nanostructured Diamond  Powders for Advanced Separations

High surface area, electrically-conducting and corrosion-resistant nanodiamond and nanodiamond/graphene composite powders are being prepared by chemical vapor deposition using a core-shell approach. Depending on the substrate used, the resulting powders can have surface areas in the 100-200 m2/g range and electrical conductivities greater than 0.5 S/cm.

In terms of separations, new research involves the use of these conducting powders as a stationary phase material in electrochemically-modulated liquid chromatography (EMLC). In this method, the stationary phase is made into a working electrode on the column and solute retention is studied as a function of the potential applied to the stationary phase and the temperature. EMLC is being used  to better understand (i) the double layer structure formed at these diamond powders in aqueous media and (ii) the thermodynamics of molecular (electrostatic) interactions with the carbon material surface. Powders with various chemical modification are being studied (e.g., H, O, NH2).

Diamond is an excellent material for use in chromatography because it is the hardest material on earth and it is stable under a wide range of temperatures and pH levels. In theory, diamond and functionalized diamond should offer superior performance to silica and functionalized silica. The inertness of diamond may allow it to be used with biologically-sensitive samples that are often pH sensitive and can easily foul a column. In addition, diamond-based stationary phases should allow for the exploration of novel chemistries. To this end, new research is exploring the use of micrometer diamond and functionalized diamond powders as a stationary phase for reversed- and normal-phase liquid chromatography. Potential exists to use diamond as a novel stationary phase for solid phase extractions (SPE).