Other Chemistry Commons^™

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Temperature-Pressure Phase Diagram Of Confined Monolayer Water/Ice At First-Principles Accuracy With A Machine-Learning Force Field, Bo Lin, Jian Jiang, Xiao Cheng Zeng, Lei Li

Department of Chemistry: Faculty Publications

Understanding the phase behaviour of nanoconfined water films is of fundamental importance in broad fields of science and engineering. However, the phase behaviour of the thinnest water film – monolayer water – is still incompletely known. Here, we developed a machine-learning force field (MLFF) at first-principles accuracy to determine the phase diagram of monolayer water/ice in nanoconfinement with hydrophobic walls. We observed the spontaneous formation of two previously unreported high-density ices, namely, zigzag quasi-bilayer ice (ZZ-qBI) and branched-zigzag quasi-bilayer ice (bZZ-qBI). Unlike conventional bilayer ices, few inter-layer hydrogen bonds were observed in both quasi-bilayer ices. Notably, the bZZ-qBI entails a …

Long-Term Degradation Mechanisms In Application-Implemented Radical Thin Films, Ewa Malgorzata Nowik-Boltyk, Tobias Junghoefer, Mathias Glaser, Erika Giangrisostomi, Ruslan Ovsyannikov, Shuyang Zhang, Chan Shu, Andrzej Rajca, Arrigo Calzolari, M. Benedetta Casu

Department of Chemistry: Faculty Publications

Blatter radical derivatives are very attractive due to their potential applications, ranging from batteries to quantum technologies. In this work, we focus on the latest insights regarding the fundamental mechanisms of radical thin film (long-term) degradation, by comparing two Blatter radical derivatives. We find that the interaction with different contaminants (such as atomic H, Ar, N, and O and molecular H₂, N₂, O₂, H₂O, and NH₂) affects the chemical and magnetic properties of the thin films upon air exposure. Also, the radical-specific site, where the contaminant interaction takes place, plays …

Stepwise Assembly Of Quinary Multivariate Metal−Organic Frameworks Via Diversified Linker Exchange And Installation, Yuchen Hu, Xin Zhang, Rebecca Shu Hui Khoo, Christian Fiankor, Xu Zhang, Jian Zhang

Department of Chemistry: Faculty Publications

Multivariate MOFs (MTV-MOFs) constructed from multiple components with atomistic precision hold the promise for many fascinating developments in both fundamental sciences and applications. Sequential linker installation can be an effective method to introduce different functional linkers into an MOF that contains coordinatively unsaturated metal sites. However, in many cases, these linkers must be installed according to a specific sequence and the complete synthetic flexibility and freedom is yet to be realized. Here, we rationally decreased the size of the primary ligand used in NPF-300, a Zr-MOF with scu topology (NPF = Nebraska Porous Framework), and synthesized its isostructure, NPF-320. NPF-320 …

Nanoscale Imaging Of Electrocatalytic Nanomaterials By High-Resolution Scanning Electrochemical Microscopy, Xiang Wang

Dissertations, Theses, and Capstone Projects

Numerous insights of the structure–electrochemical activity relationship of nanocatalysts have been obtained by using macroscopic electrochemical measurements over the last several decades. However, signals measured by large electrodes are inevitably averaged out of many nanocatalysts, non-uniformed sizes, uneven morphologies, and multiple crystallographic facets. Over the last ten years, Scanning Electrochemical Microscopy (SECM) has advanced electrochemical measurements toward micro- to nanoscale level at a high spatial resolution. The advantages of using nanoelectrode in SECM include fast mass transfer of reactive species, dominated radial diffusion pattern, small double layer capacitance and small RC constant. In this thesis, high-resolution SECM is applied to …

Ultra-Fast Bioorthogonal Spin-Labeling And Distance Measurements In Mammalian Cells Using Small, Genetically Encoded Tetrazine Amino Acids, Subhashis Jana, Eric G. B. Evans, Hyo Sang Jang, Shuyang Zhang, Hui Zhang, Andrzej Rajca, Sharona E. Gordon, William N. Zagotta, Stefan Stoll, Ryan A. Mehl

Department of Chemistry: Faculty Publications

Studying protein structures and dynamics directly in the cellular environments in which they function is essential to fully understand the molecular mechanisms underlying cellular processes. Site-directed spin-labeling (SDSL)—in combination with double electron–electron resonance (DEER) spectroscopy—has emerged as a powerful technique for determining both the structural states and the conformational equilibria of biomacromolecules. In-cell DEER spectroscopy on proteins in mammalian cells has thus far not been possible due to the notable challenges of spin-labeling in live cells. In-cell SDSL requires exquisite biorthogonality, high labeling reaction rates and low background signal from unreacted residual spin label. While the bioorthogonal reaction must be …

Electronic Transport Properties Of Spin-Crossover Polymer Plus Polyaniline Composites With Fe3O4 Nanoparticles, Esha Mishra, Waikiat Chin, Kayleigh A. Mcelveen, Thilini K. Ekanayaka, M. Zaid Zaz, Gauthami Viswan, Ruthi Zielinski, Alpha T. N'Diaye, David Shapiro, Rebecca Lai, Robert Streubel, Peter A. Dowben

Department of Chemistry: Faculty Publications

Adding Fe₃O₄ nanoparticles to composites of [Fe(Htrz)₂(trz)](BF₄) spin-crossover polymer and polyaniline (PANI) drives a phase separation of both and restores the molecular structure and cooperative effects of the spin-crossover polymer without compromising the increased conductivity gained through the addition of PANI. We observe an increased on-off ratio for the DC conductivity owing to an enlarged off state resistivity and a 20 times larger AC conductivity of the on state compared with DC values. The Fe₃O₄ nanoparticles, primarily confined to the [Fe(Htrz)₂(trz)](BF₄) phase, are ferromagnetically coupled to …

Progress In 7sk Ribonucleoprotein Structural Biology, Momodou B. Camara, Amr M. Sobeh, Catherine D. Eichhorn

Department of Chemistry: Faculty Publications

The 7SK ribonucleoprotein (RNP) is a dynamic and multifunctional regulator of RNA Polymerase II (RNAPII) transcription in metazoa. Comprised of the noncoding 7SK RNA, core proteins, and numerous accessory proteins, the most wellknown 7SK RNP function is the sequestration and inactivation of the positive transcription elongation factor b (P-TEFb). More recently, 7SK RNP has been shown to regulate RNAPII transcription through P-TEFb-independent pathways. Due to its fundamental role in cellular function, dysregulation has been linked with human diseases including cancers, heart disease, developmental disorders, and viral infection. Significant advances in 7SK RNP structural biology have improved our understanding of 7SK …

Exploring The Complementarity Of Measures Of Instructional Practices, Lu Shi, Robert M. Erdmann, Anthony Pellegrini, Victoria Johnson, Binh Le, Trina Popple, Zachary Nelson, Molly Undersander Gaston, Marilyne Stains

Department of Chemistry: Faculty Publications

The assessment of instructional quality has been and continues to be a desirable, yet difficult endeavor in higher education. The development of new teaching evaluation frameworks along with instruments to measure various aspects of teaching practices holds promise. The challenge rests in the implementation of these frameworks and measures in authentic settings. Part of this challenge is for instructors, researchers, and administrators to parse through and select a meaningful set of tools from the plethora of existing instruments. In this study, we aim to start clarifying the landscape of measures of instructional practice by exploring the complementarity of two existing …

Interpretation Of The Tandem Mass Spectrum Of The Novel Psychoactive Substance 5f-App-Pinaca, Px-2, Christopher S. Poulos

Graduate Theses, Dissertations, and Problem Reports (ETD)

Designer drugs and novel psychoactive substances (NPSs) are continuously entering the black market and causing serious health problems among users. NPSs present an especially difficult challenge to forensic chemists and toxicologists because they are not well characterized and often involve families of structurally related analogs. In crime laboratories, mass spectrometry is commonly used as a part of an analytical scheme to characterize and identify unknown analytes. Towards this end, tandem mass spectra of questioned analytes are often compared to reference spectra of standards that are either collected contemporaneously with the analyte or collected previously and stored in a database. However, …

Enhancing The Forensic Comparison Process Of Common Trace Materials Through The Development Of Practical And Systematic Methods, Meghan Nicole Prusinowski

Graduate Theses, Dissertations, and Problem Reports (ETD)

An ongoing advancement in forensic trace evidence has driven the development of new and objective methods for comparing various materials. While many standard guides have been published for use in trace laboratories, different areas require a more comprehensive understanding of error rates and an urgent need for harmonizing methods of examination and interpretation. Two critical areas are the forensic examination of physical fits and the comparison of spectral data, which depend highly on the examiner’s judgment.

The long-term goal of this study is to advance and modernize the comparative process of physical fit examinations and spectral interpretation. This goal is …

Multiomics Approach Captures Hepatic Metabolic Network Altered By Chronic Ethanol Administration, Isin Tuna Sakallioglu, Bridget Tripp, Jacy Kubik, Carol A. Casey, Paul G. Thomes, Robert Powers

Department of Chemistry: Faculty Publications

Using a multiplatform and multiomics approach, we identified metabolites, lipids, proteins, and metabolic pathways that were altered in the liver after chronic ethanol administration. A functional enrichment analysis of the multiomics dataset revealed that rats treated with ethanol experienced an increase in hepatic fatty acyl content, which is consistent with an initial development of steatosis. The nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography–mass spectrometry (LC-MS) metabolomics data revealed that the chronic ethanol exposure selectively modified toxic substances such as an increase in glucuronidation tyramine and benzoyl; and a depletion in cholesterol-conjugated glucuronides. Similarly, the lipidomics results revealed that ethanol …

Uv-Light-Tunable P-/N-Type Chemiresistive Gas Sensors Based On Quasi-1d Tis3 Nanoribbons: Detection Of Isopropanol At Ppm Concentrations, Victor V. Sysoev, Andrey V. Lashkov, Alexey Lipatov, Ilya A. Plugin, Michael Bruns, Dirk Fuchs, Alexey S. Varezhnikov, Mustahsin Adib, Martin Sommer, Alexander Sinitskii

Department of Chemistry: Faculty Publications

The growing demand of society for gas sensors for energy-efficient environmental sensing stimulates studies of new electronic materials. Here, we investigated quasi-one-dimensional titanium trisulfide (TiS₃) crystals for possible applications in chemiresistors and on-chip multisensor arrays. TiS₃ nanoribbons were placed as a mat over a multielectrode chip to form an array of chemiresistive gas sensors. These sensors were exposed to isopropanol as a model analyte, which was mixed with air at low concentrations of 1–100 ppm that are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit. The tests were performed at room temperature (RT), as …

Threonine Phosphorylation Of An Electrochemical Peptide-Based Sensor To Achieve Improved Uranyl Ion Binding Affinity, Channing C. Thompson, Rebecca Lai

Department of Chemistry: Faculty Publications

We have successfully designed a uranyl ion (U(VI)-specific peptide and used it in the fabrication of an electrochemical sensor. The 12-amino acid peptide sequence, (n) DKDGDGYIpTAAE (c), originates from calmodulin, a Ca(II)-binding protein, and contains a phosphothreonine that enhances the sequence’s affinity for U(VI) over Ca(II). The sensing mechanism of this U(VI) sensor is similar to other electrochemical peptide-based sensors, which relies on the change in the flexibility of the peptide probe upon interacting with the target. The sensor was systematically characterized using alternating current voltammetry (ACV) and cyclic voltammetry. Its limit of detection was 50 nM, which is lower …

Fine Tuning The Pore Surface In Zirconium Metal−Organic Frameworks For Selective Ethane/Ethylene Separation, Yuchen Hu, Yanshu Shi, Yi Xie, Rebecca Shu Hui Khoo, Christian Fiankor, Xu Zhang,, Banglin Chen, Jian Zhang

Department of Chemistry: Faculty Publications

Ethylene is an important chemical feedstock for production of polymers and high-value organic chemicals, and yet its conventional purification process is plagued with high consumption of energy. Metal−organic frameworks (MOFs) provide a suitable adsorption platform for selective ethane/ ethylene separation thanks to their structural diversity, tunable pore characteristics, designable pore sizes, and high pore volumes. Although there are empirical design rules like avoiding open metal sites and creating nonpolar pore surfaces for development of adsorptive MOFs, it is still challenging to design robust MOFs that can realize direct ethane-selective separation. Herein, we systematically designed and synthesized three Zr-MOFs based on …

Leveraging The Structure Of Dnaja1 To Discover Novel Potential Pancreatic Cancer Therapies, Heidi E. Roth, Aline De Lima Leite, Nicolas Y. Palermo, Robert Powers

Department of Chemistry: Faculty Publications

Pancreatic cancer remains one of the deadliest forms of cancer with a 5-year survival rate of only 11%. Difficult diagnosis and limited treatment options are the major causes of the poor outcome for pancreatic cancer. The human protein DNAJA1 has been proposed as a potential therapeutic target for pancreatic cancer, but its cellular and biological functions remain unclear. Previous studies have suggested that DNAJA10s cellular activity may be dependent upon its protein binding partners. To further investigate this assertion, the first 107 amino acid structures of DNAJA1 were solved by NMR, which includes the classical J-domain and its associated linker …

Ai Protein Structure Prediction-Based Modeling And Mutagenesis Of A Protostome Receptor And Peptide Ligands Reveal Key Residues For Their Interaction, Shi-Qi Guo, Ya-Dong Li, Ping Chen, Guo Zhang, Hui-Ying Wang, Hui-Min Jiang, Wei-Jia Liu, Ju-Ping Xu, Xue-Ying Ding, Ping Fu, Ke Yu, Hai-Bo Zhou, James W. Checco, Jian Jing

Department of Chemistry: Faculty Publications

The protostome leucokinin (LK) signaling system, including LK peptides and their G protein-coupled receptors, has been characterized in several species. Despite the progress, molecular mechanisms governing LK peptide–receptor interactions remain to be elucidated. Previously, we identified a precursor protein for Aplysia leucokinin-like peptides (ALKs) that contains the greatest number of amidated peptides among LK precursors in all species identified so far. Here, we identified the first ALK receptor from Aplysia, ALKR. We used cell-based IP1 activation assays to demonstrate that two ALK peptides with the most copies, ALK1 and ALK2, activated ALKR with high potencies. Other endogenous ALK-derived peptides …

Meta-Analysis Reveals Both The Promises And The Challenges Of Clinical Metabolomics, Heidi E. Roth, Robert Powers

Department of Chemistry: Faculty Publications

Clinical metabolomics is a rapidly expanding field focused on identifying molecular biomarkers to aid in the efficient diagnosis and treatment of human diseases. Variations in study design, metabolomics methodologies, and investigator protocols raise serious concerns about the accuracy and reproducibility of these potential biomarkers. The explosive growth of the field has led to the recent availability of numerous replicate clinical studies, which permits an evaluation of the consistency of biomarkers identified across multiple metabolomics projects. Pancreatic ductal adenocarcinoma (PDAC) is the third-leading cause of cancer-related death and has the lowest five-year survival rate primarily due to the lack of an …

Editorial: Expansion Of The Genetic Code: Unnatural Amino Acids And Their Applications, Subhendu Sekhar Bag, Ishu Saraogi, Jiantao Guo

Department of Chemistry: Faculty Publications

No abstract provided.

Nmr And Metabolomics—A Roadmap For The Future, David S. Wishart, Leo L. Cheng, Valérie Copié, Arthur S. Edison, Hamid R. Eghbalnia, Jeffrey C. Hoch, Goncalo J. Gouveia, Wimal Pathmasiri, Robert Powers, Tracey B. Schock, Lloyd W. Sumner, Mario Uchimiya

Department of Chemistry: Faculty Publications

Metabolomics investigates global metabolic alterations associated with chemical, biological, physiological, or pathological processes. These metabolic changes are measured with various analytical platforms including liquid chromatography-mass spectrometry (LC-MS), gas chromatographymass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). While LC-MS methods are becoming increasingly popular in the field of metabolomics (accounting for more than 70% of published metabolomics studies to date), there are considerable benefits and advantages to NMR-based methods for metabolomic studies. In fact, according to PubMed, more than 926 papers on NMR-based metabolomics were published in 2021—the most ever published in a given year. This suggests that NMR-based metabolomics …

Negative Photoresponse In Ti3C2TX Mxene Monolayers, Nataliia S. Vorobeva, Saman Bagheri, Angel Torres, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Two-dimensional transition metal carbides, nitrides, and carbonitrides, collectively known as MXenes, are finding numerous applications in many different areas, including optoelectronics and photonics, but there is limited information about their intrinsic photoresponse. In this study, we investigated the visible and near-infrared range photoresponse of Ti₃C₂T_x, the most popular MXene material to date. The electrical measurements were performed on devices based on individual monolayer Ti₃C₂T_x MXene flakes, which were characterized by a variety of microscopic and spectroscopic methods. For MXene devices with different electrode layouts, the current reproducibly decreased under …

Characterization Of Three-Dimensional Fractional Viscoelastic Models Through Complex Modulus Analysis And Polar Decomposition, Avradip Ghosh, Avinash Kumar Both, Chin Li Cheung

Department of Chemistry: Faculty Publications

Soft materials such as gels, elastomers, and biological tissues have diverse applications in nature and technology due to their viscoelastic nature. These soft materials often exhibit complex rheology and display elastic and viscous characteristics when undergoing deformation. In recent years, fractional calculus has emerged as a promising tool to explain the viscoelastic behavior of soft materials. Scalar constants are primarily used to quantify viscoelastic elements such as springs and dashpots. However, in three-dimensional (3D) space, not all materials show the same elastic or viscoelastic properties in all directions, especially under elastic/viscoelastic wave propagation (or anisotropy). Though previously reported studies on …

Multiplexed Monitoring Of Neurochemicals Via Electrografting- Enabled Site-Selective Functionalization Of Aptamers On Field-Effect Transistors, Zan Gao, Guangfu Wu, Yang Song, Huijie Li, Yuxuan Zhang, Michael J. Schneider, Yingqi Qiang, Jackson Kaszas, Zhengyan Weng, He Sun, Bryan D. Huey, Rebecca Lai, Yi Zhang

Department of Chemistry: Faculty Publications

Neurochemical corelease has received much attention in understanding brain activity and cognition. Despite many attempts, the multiplexed monitoring of coreleased neurochemicals with spatiotemporal precision and minimal crosstalk using existing methods remains challenging. Here, we report a soft neural probe for multiplexed neurochemical monitoring via the electrografting-assisted site-selective functionalization of aptamers on graphene field-effect transistors (G-FETs). The neural probes possess excellent flexibility, ultralight mass (28 mg), and a nearly cellular-scale dimension of 50 μm × 50 μm for each G-FET. As a demonstration, we show that G-FETs with electrochemically grafted molecular linkers (−COOH or −NH2) and specific aptamers can be used …

Asymmetrical Spectral Continuum Between Anti-Stokes And Stokes Scattering Revealed In Low-Frequency Surface-Enhanced Raman Spectroscopy, Shuo Sun, Dhanusha T.N. Rathnayake, Yinsheng Guo

Department of Chemistry: Faculty Publications

An asymmetrical spectral continuum is observed in low-frequency surface-enhanced Raman spectroscopy (LF-SERS) in the terahertz (THz) region. This background continuum appears as a flat baseline in the Stokes side and a slope in the anti-Stokes side. Analysis shows this asymmetry originates from the different scaling of anti-Stokes and Stokes scattering with respect to the Bose−Einstein distribution. Such asymmetry is readily visible, under room temperature, in the low-frequency THz spectral range. Accounting for this spectral intensity asymmetry reveals the intrinsic continuum background of electronic origin, differing from local normal modes and collective relaxational motions. We also describe a numerical method, independent …

Noncanonical Amino Acid Mutagenesis In Response To Recoding Signal-Enhanced Quadruplet Codons, Yan Chen, Xinyuan He, University Of Nebraska-Lincoln, Kun Liu, Tian Gao, Wei Niu, Jiantao Guo

Department of Chemistry: Faculty Publications

While amber suppression is the most common approach to introduce noncanonical amino acids into proteins in live cells, quadruplet codon decoding has potential to enable a greatly expanded genetic code with up to 256 new codons for protein biosynthesis. Since triplet codons are the predominant form of genetic code in nature, quadruplet codon decoding often displays limited efficiency. In this work, we exploited a new approach to significantly improve quadruplet UAGN and AGGN (N = A, U, G, C) codon decoding efficiency by using recoding signals imbedded in mRNA. With representative recoding signals, the expression level of mutant proteins containing …

Advanced Cnc/Peg/Pdmaa Semi-Ipn Hydrogel For Drug Delivery Management In Wound Healing, Samia Afrin, Md. Shahruzzaman, Papia Haque, Md. Sazedul Islam, Shafiul Hossain, Taslim Ur Rashid, Tanvir Ahmed, Makoto Takafuji, Mohammed Mizanur Rahman

Department of Chemistry: Faculty Publications

A Semi Interpenetrating Polymer Network (semi-IPN) hydrogel was prepared and loaded with an antibiotic drug, gentamicin, to investigate the wound healing activity of this system. The semi-IPN hydrogel was synthesized by combining natural polymer cellulose nanocrystal (CNC) and synthetic polymer polyethylene glycol (PEG) and poly (N,N0-dimethyl acrylamide) (PDMAA), which was initially added as a monomer dimethyl acrylamide (DMAA). CNC was prepared from locally obtained jute fibers, dispersed in a PEG-NaOH solvent systemand then mixed with monomer DMAA, where polymerization was initiated by an initiator potassium persulphate (KPS) and cross-linked by N,N0-methylenebisacrylamide (NMBA). The size, morphology, biocompatibility, antimicrobial activity, thermal and …

Understanding The Effects Of Temperature On Electrostatic Dna Denaturation, Jeffrey Taylor

Master's Theses

In this work, the electrostatic denaturation of 18-bp DNA duplexes was investigated via Square Wave Voltammetry (SWV) to determine the extent of melting (∆) and rate of melting (𝝉). Electrostatic denaturation was observed over the temperature range of 20-50 °C, and purely electrostatic melting was defined from 27.5°C. In contrast, electrostatic denaturation for 30 °C was defined as a mixture of thermal melting thiol desorption + electrostatic melting. Electrostatic denaturation is a temperature-dependent process, and the amount of melting of the dsDNA increased with temperature. It was also observed that the ∆ and 𝝉 values increase with temperature further …

Biomaterials: From Scaffold Design To Implant Optimization, Jennifer Marie Armen

Electronic Theses and Dissertations

This work encompasses three individual projects concerning biomaterials and their modifications. Chemically-Induced Cross-Linking of Peptidic Fibrils for Scaffolding Polymeric Particles and Macrophages EAK16-II (EAK) is a self-assembling peptide (SAP) that forms β-sheets and βfibrils through ionic-complementary interactions at physiological ionic strengths. The soft materials can be injected in vivo, creating depots of drugs and cells for rendering pharmacological and biological actions. The scope of the applications of EAK is sought to extend to tissues through which the flow of extracellular fluid tends to be limited. In such anatomical locales the rate and extent of the fibrilization are limited insofar as …

Comparing And Contrasting Therapeutic Drugs Vs. Lifestyle Changes That Combattype-Ii Diabetes, Alexander Cline Helmuth

Chemistry & Biochemistry Student Projects

In this thesis, I will be presenting various preventive approaches to combat type-II diabetes. The focus of this paper will be comparing and contrasting therapeutic drug targets such as Metformin and Sulfonylureas that are prescribed for type-II diabetic patients versus taking preventative steps such as making lifestyle changes including weight management, physical activity, and having a balanced diet that prevents onset of type-II diabetes or helps patients manage type-II diabetes. From this paper, one will gain insight on how there are multiple approaches to combat type-II diabetes that are not in the form of the pill.

Microfluidic Paper Analytical Devices, Madison Page

Chemistry & Biochemistry Student Projects

Microfluidic paper analytical devices (µPADs) are small, paper-based matrices similar to Lab-on-a-Chip (LOC). They are capable of semi-quantitative analysis, with applications ranging from medical to environmental to food and beverage testing. Important to improving point-of-care devices (POCs), various techniques have been integrated into µPADs to customize analysis and fit different clinical situations.