John Goodpaster

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https://hdl.handle.net/1805/6679

Evaluation of the Odor Compounds Sensed by Explosive-Detecting Canines

The remote detection of explosives generally relies upon detecting volatile compounds that are emitted by the explosive itself. Detection of these compounds can be achieved through instrumentation or by specially trained canines. While instruments are designed and built to respond to particular chemical species, it is not always clear what chemical species generates a canine alert. In addition, canines have the ability to "generalize" and correctly alert to explosive formulations that are similar, but not identical, to those with which they have trained. This would tend to indicate that there are common chemical odors for some types of explosives. Dr. Goodpaster's research examines the effect of odor availability and differing odor compounds on canine detection. As the chemical composition of the headspace above explosive formulations is more completely understood, it should be possible to test the extent to which canine alerts correlate to the compounds of interest.

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Enhancing Nonfouling and Sensitivity of Surface-Enhanced Raman Scattering Substrates for Potent Drug Analysis in Blood Plasma via Fabrication of a Flexible Plasmonic Patch
(ACS, 2021-01) Masterson, Adrianna N.; Hati, Sumon; Ren, Greta; Liyanage, Thakshila; Manicke, Nicholas E.; Goodpaster, John V.; Sardar, Rajesh; Chemistry and Chemical Biology, School of Science
Surface-enhanced Raman scattering (SERS) is an ultrasensitive analytical technique, which is capable of providing high specificity; thus, it can be used for toxicological drug assay (detection and quantification). However, SERS-based drug analysis directly in human biofluids requires mitigation of fouling and nonspecificity effects that commonly appeared from unwanted adsorption of endogenous biomolecules present in biofluids (e.g., blood plasma and serum) onto the SERS substrate. Here, we report a bottom-up fabrication strategy to prepare ultrasensitive SERS substrates, first, by functionalizing chemically synthesized gold triangular nanoprisms (Au TNPs) with poly(ethylene glycol)-thiolate in the solid state to avoid protein fouling and second, by generating flexible plasmonic patches to enhance SERS sensitivity via the formation of high-intensity electromagnetic hot spots. Poly(ethylene glycol)-thiolate-functionalized Au TNPs in the form of flexible plasmonic patches show a twofold-improved signal-to-noise ratio in comparison to triethylamine (TEA)-passivated Au TNPs. Furthermore, the plasmonic patch displays a SERS enhancement factor of 4.5 ×107. Utilizing the Langmuir adsorption model, we determine the adsorption constant of drugs for two different surface ligands and observe that the drug molecules display stronger affinity for poly(ethylene glycol) ligands than TEA. Our density functional theory calculations unequivocally support the interaction between drug molecules and poly(ethylene glycol) moieties. Furthermore, the universality of the plasmonic patch for SERS-based drug detection is demonstrated for cocaine, JWH-018, and opioids (fentanyl, despropionyl fentanyl, and heroin) and binary mixture (trace amount of fentanyl in heroin) analyses. We demonstrate the applicability of flexible plasmonic patches for the selective assay of fentanyl at picogram/milliliter concentration levels from drug-of-abuse patients’ blood plasma. The fentanyl concentration calculated in the patients’ blood plasma from SERS analysis is in excellent agreement with the values determined using the paper spray ionization mass spectrometry technique. We believe that the flexible plasmonic patch fabrication strategy would be widely applicable to any plasmonic nanostructure for SERS-based chemical sensing for clinical toxicology and therapeutic drug monitoring.
Classification Strategies for Fusing UV/visible Absorbance and Fluorescence Microspectrophotometry Spectra from Textile Fibers
(Cambridge UP, 2018-08) Fuenffinger, Nathan; Goodpaster, John V.; Bartick, Edward G.; Morgan, Stephen L.; Chemistry and Chemical Biology, School of Science
Preparation, characterization, and application of a lipophilic coated exfoliated Egyptian blue for near-infrared luminescent latent fingermark detection
(Forensic Chemistry, 2020-05-01) Shahbazi, Sorour; Goodpaster, John V.; Smith, Gregory D.; Becker, Thomas; Lewis, Simon W.
A simple technique is described to create nanoscale near-infrared luminescent Egyptian blue pigment particles with lipophilic surfaces for latent fingermark detection. An exfoliated Egyptian blue powder coated with cetrimonium bromide was prepared using a simple, one-pot process. Particle size and surface coatings were characterized using scanning electron and atomic force microscopies, dynamic light scattering, and infrared and luminescence spectroscopies. This new fingermark dusting powder presents more contrast compared to uncoated Egyptian blue of comparable particle size as well as a commercial visible light fluorescent (Blitz Red) powder in the detection of aged fingermarks on model surfaces. The coated Egyptian blue pigment is a cost-effective fingermark dusting powder that reveals high contrast latent fingermarks with simple, inexpensive photography equipment.
Tracking the Progression of Triple Negative Mammary Tumors over Time by Chemometric Analysis of Urinary Volatile Organic Compounds
(Cancers, 2021-01) Woollam, Mark; Wang, Luqi; Grocki, Paul; Liu, Shengzhi; Siegel, Amanda P.; Kalra, Maitri; Goodpaster, John V.; Yokota, Hiroki; Agarwal, Mangilal
Previous studies have shown that volatile organic compounds (VOCs) are potential biomarkers of breast cancer. An unanswered question is how urinary VOCs change over time as tumors progress. To explore this, BALB/c mice were injected with 4T1.2 triple negative murine tumor cells in the tibia. This typically causes tumor progression and osteolysis in 1–2 weeks. Samples were collected prior to tumor injection and from days 2–19. Samples were analyzed by headspace solid phase microextraction coupled to gas chromatography–mass spectrometry. Univariate analysis identified VOCs that were biomarkers for breast cancer; some of these varied significantly over time and others did not. Principal component analysis was used to distinguish Cancer (all Weeks) from Control and Cancer Week 1 from Cancer Week 3 with over 90% accuracy. Forward feature selection and linear discriminant analysis identified a unique panel that could identify tumor presence with 94% accuracy and distinguish progression (Cancer Week 1 from Cancer Week 3) with 97% accuracy. Principal component regression analysis also demonstrated that a VOC panel could predict number of days since tumor injection (R2 = 0.71 and adjusted R2 = 0.63). VOC biomarkers identified by these analyses were associated with metabolic pathways relevant to breast cancer.
Monitoring compositional changes of the lipid fraction of fingermark residues deposited on paper during storage
(Forensic Chemistry, 2016-11-01) Frick, A.A.; Chidlow, G.; Goodpaster, John V.; Lewis, S.W.; van Bronswijk, W.
Characterising the changes in fingermark composition as a function of time is of great value for improving fingermark detection capabilities by understanding the processes and circumstances under which target compounds become degraded. In this study, gas chromatography-mass spectrometry was used to monitor relative changes in the lipids from latent fingermarks over 28 days. Principal component analysis of the relative composition of 15 lipids in fingermarks showed that fingermark age was a significant contributor to the variability observed in the data, but that inter-donor variability was also significant. This was attributed principally to changes in the relative amounts of squalene, which rapidly decreased in the fingermarks. It was also observed, however, that most fingermarks exhibited relatively small changes in composition during the first seven days, followed by more rapid changes up to 28 days. Significant inter-donor variation of both initial fingermark composition and the rates and nature of loss processes was observed, which was reflected in the relative projection of samples from different donors. Finally, samples stored with no exposure to light or airflow for 28 days were projected significantly closer to the samples analysed on the day of deposition than those exposed to light, due to the reduced photodegradation rate of squalene.
Studies into Exfoliation and Coating of Egyptian Blue for Application to the Detection of Latent Fingermarks
(Chem Rxiv, 2020-09-23) Shahbazi, Sorour; Goodpaster, John V.; Smith, Gregory; Becker, Thomas; Lewis, Simon W.
We have recently demonstrated that exfoliated Egyptian blue powder coated with cetrimonium bromide is effective for detecting latent fingermarks on a range of highly-patterned non-porous surfaces (see reference). In this extension of that work, we here present our preliminary studies into alternative approaches to preparing exfoliated Egyptian blue with a variety of different coatings. The various powders were then applied to the detection of latent fingermarks on non-porous surfaces. This proof of concept study demonstrated that there is potential improvement in performance compared to our previous work, however more comprehensive studies are required to compare the quality of the fingermarks developed with these powders against particles exfoliated in water.
Automated Derivatization and Identification of Controlled Substances via Total Vaporization Solid Phase Microextraction (TV-SPME) and Gas Chromatography/Mass Spectrometry (GC/MS)
(U.S. Department of Justice, Office of Justice Programs, 2018-11) Goodpaster, John V.
The hypothesis tested was that Total Vaporization - Solid Phase Microextraction (TV-SPME) will offer greater sensitivity than traditional liquid injection for controlled substances. In addition, TV-SPME was easily adapted to include either a pre-extraction or a post-extraction on-fiber derivatization step for thermally labile species. Project results were promising for all drug classes that were analyzed successfully by on-fiber derivatization as solutions. This discovery greatly improves the utility of the technique, since controlled substances are most often encountered in their solid forms in forensic science laboratories. The application of this technique to beverage samples and solid drug powders is of most interest, since these applications involve a significant decrease in sample preparation. Although not ideal for all analytes, TV-SPME with on-fiber derivatization could be a powerful technique for amine and hydroxylamine controlled substances, as well as GHB. The technique could increase analyst efficiency by reducing sample preparation time for these types of analytes. Thus, the main results of this project are a set of optimized derivatization methods that can be used in liquid injection or TV-SPfsME. This approach offers the possibility of automated sampling and derivatization for a wide variety of thermally labile compounds and the analysis of compounds that require no derivatization. Project design and methods are described. 4 figures and 1 table
Differentiation of Structurally Similar Phenethylamines via Gas Chromatography - Vacuum Ultraviolet Spectroscopy (GC – VUV)
(Elsevier, 2019-08) Roberson, Zackery R.; Goodpaster, John V.; Chemistry and Chemical Biology, School of Science
The vacuum ultraviolet region includes wavelengths shorter than 200 nm. Electronic transitions of sigma and pi bonds lie in this region, which have the potential to yield structural information. Thus, a VUV detector should be able to detect nearly any molecule analyzable by gas chromatography. This study sought to determine the extent to which structurally similar phenethylamines are differentiated using their VUV spectra. Phenethylamines are a common drug class including pseudoephedrine and illicit drugs such as methamphetamine. Several phenethylamines are difficult to analyze by electron impact mass spectrometry due to their fragmentation giving the same mass to charge ratio fragments at similar ratios. While phenethylamines are generally differentiable by retention time, an extra layer of specificity is preferred in forensic analyses. A vacuum ultraviolet (VUV) spectrophotometer coupled to a gas chromatograph was used to collect VUV spectra at high frequency between 125 and 430 nm. Eight phenethylamines were analyzed for this work using GC/VUV. A calibration curve and limit of detection study was performed that indicates a limit of detection around 10 μg mL−1 and an upper limit of linearity around 1000 μg mL−1. The spectra, analyzed by Principal Component Analysis and Discriminant Analysis, indicate the ability to reliably differentiate each of the drugs from one another including structural isomers and diastereomers. Lastly, five “street” samples containing amphetamines were analyzed to demonstrate “real world” performance.
Preparation and characterization of micro-bore wall-coated open-tubular capillaries with low phase ratios for fast-gas chromatography–mass spectrometry: Application to ignitable liquids and fire debris
(Elsevier, 2019) Roberson, Zackery R.; Goodpaster, John V.; Chemistry and Chemical Biology, School of Science
Fast Gas Chromatography (GC) allows for analysis times that are a fraction of those seen in traditional capillary GC. Key modifications in fast GC include using narrow, highly efficient columns that can resolve mixtures using a shorter column length. Hence, a typical fast GC column has an inner diameter of 100–180 μm. However, to maintain phase ratios that are consistent with typical GC columns, the film thickness of fast GC stationary phases are also low (e.g., 0.1–0.18 μm). Unfortunately, decreased film thickness leads to columns with very low sample capacity and asymmetric peaks for analytes that are not sufficiently dilute. This paper describes micro-bore (50 μm i.d.) capillary columns with thick films (1.25 μm), and low phase ratios (10). These columns have greater sample capacity yet also achieve minimum plate heights as low as 110 μm. Hence, separation efficiency is much higher than would be obtained using standard GC columns. The capillary columns were prepared in-house using a simple static-coating procedure and their plate counts were determined under isothermal conditions. The columns were then evaluated using temperature programming for fast GC–MS analysis of ignitable liquids and their residues on fire debris exemplars. Temperature ramps of up to 75 °C min−1 could be used and separations of ignitable liquids such as gasoline, E85 fuel, and lighter fluid (a medium petroleum distillate) were complete within 3 min. Lastly, simulated fire debris consisting of ignitable liquids burned on carpeting were extracted using passive headspace absorption-elution and the residues successfully classified.
Fabrication of a Self-Assembled and Flexible SERS Nanosensor for Explosive Detection at Parts-Per-Quadrillion Levels from Fingerprints
(RSC, 2018-05) Liyanage, Thakshila; Rael, Ashur; Shaffer, Sidney; Zaidi, Shozaf; Goodpaster, John V.; Sardar, Rajesh; Chemistry and Chemical Biology, School of Science
Apart from high sensitivity and selectivity of surface-enhanced Raman scattering (SERS)-based trace explosive detection, efficient sampling of explosive residue from real world surfaces is very important for homeland security applications. Herein, we demonstrate an entirely new SERS nanosensor fabrication approach. The SERS nanosensor was prepared by self-assembling chemically synthesized gold triangular nanoprisms (Au TNPs), which we show display strong electromagnetic field enhancements at the sharp tips and edges, onto a pressure-sensitive flexible adhesive film. Our SERS nanosensor provides excellent SERS activity (enhancement factor = ∼6.0 × 106) and limit of detection (as low as 56 parts-per-quadrillions) with high selectivity by chemometric analyses among three commonly military high explosives (TNT, RDX, and PETN). Furthermore, the SERS nanosensors present excellent reproducibility (<4.0% relative standard deviation at 1.0 μM concentration) and unprecedentedly high stability with a “shelf life” of at least 5 months. Finally, TNT and PETN were analyzed and quantified by transferring solid explosive residues from fingerprints left on solid surfaces to the SERS nanosensor. Taken together, the demonstrated sensitivity, selectivity, and reliability of the measurements as well as with the excellent shelf life of our SERS nanosensors obviate the need for complicated sample processing steps required for other analytical techniques, and thus these nanosensors have tremendous potential not only in the field of measurement science but also for homeland security applications to combat acts of terror and military threats.

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