bluuebunny/crossref_metadata_2025 huggingface dataset:
Fire and Smoke Characterization of Lithium-Ion Cells and Modules during Thermal Runaway
Authors: Jeevarajan Judith , Juarez Robles Daniel , Joshi Tapesh , Kathirvel Kanarindhana
Published: July 2021

Lithium-ion cell and batteries fires can vary with the nature of the chemistry, the size and volume, and the accessory components that go into making the cell or battery. A study was carried out to characterize the fire and smoke evolved during the thermal runaway of two different lithium-ion cathode chemistries of different sizes. In this case, the study included the triggering of thermal runaway of the cell, a bank of cells and a module/battery design. Another thermal runaway study was carried out on two cell formats (cylindrical and pouch) at different states-of-charge and different heating rates. Lastly a test on the cylindrical and pouch cells under an overcharge condition was also carried out. The gas samples from all the tests mentioned were also analyzed for the compositions. The results of these studies will be presented.
Deep Learning Segmentation of Operando X-Ray Microtomography of 18650 Lithium-Ion Batteries for Electric Vehicles
Authors: Allen Eva Michelle , Lim Linda Y , Liu Albert , Toney Michael F , Cabana Jordi , Weker Johanna Nelson
Published: July 2021

The US Advanced Battery Consortium goals for 2023 call for low cost, fast charge, electric vehicle (EV) batteries with a 15-minute charge time at 80% pack capacity.[1] This milestone would have a huge impact on the universal market adoption of EVs. Unfortunately, fast charging at rates above 1C, defined as the current at which it takes one hour for a battery to charge/discharge to full capacity, imposes extensive deleterious effects on current lithium-ion battery (LiB) chemistries. High charging rates aggressively accelerate degradation mechanisms owed to structural damage due to both increased cycling temperature and inhomogeneous Li ion mass transport properties. The induced electrode damage can cause void formation between the active material and conductive-binder matrix and delamination from the current collecting foil. The now electronically isolated active material results in large costs on the capacity retention of the battery.

In this study, we report measurements via operando X-ray microtomography of cylindrical cells used in EVs under simulated fast charge and drive cycles. Three batteries were measured during cycling after antecedent fast charging cycles, the 3rd, 5th, and 81st - 82nd cycles were analyzed to track morphological damage at different battery life points. To track the spatial and morphological degradation of both the anode and cathode structures, we employed a deep learning segmentation method using the U-Net convolutional neural network (CNN). Using a Euclidean Distance Mapping method, void formation is tracked spatially in 3-dimensions within the electrode coating. Insight into how fast charging induces structural damage will better inform research into fast-charge protocols and new battery chemistries for electrolytes, electrolyte additives, and novel electrode architectures.

[1]Liu, Y.; Zhu, Y.; Cui, Y. Challenges and Opportunities towards Fast-Charging Battery Materials. Nat. Energy
2019, 4 (7), 540–550. https://doi.org/10.1038/s41560-019-0405-3.
Safety Considerations of Lithium Metal Solid State Batteries
Authors: Masias Alvaro , Upadhye Mihir , Sakamoto Jeff
Published: July 2021

The advancements in Lithium Ion Batteries (LIBs) over the last three decades has significantly altered the modern world. The availability of efficient, portable electrical energy storage has enabled the proliferation of personal electronics, improved the viability of renewal energy sources such as wind and solar, and begun to transform the transportation sector.

Most next generation battery technologies, such as Lithium Metal Solid State Batteries (LMSSB), rely on the adoption of lithium metal for their improved energy storage density. The large-scale adoption of batteries using lithium metal anodes may raise safety concerns, with the properties of lithium making it unstable in the room environment. Proponents of LMSSBs often list improved safety over LIB technology due to the replacement of the flammable liquid electrolyte with an inflammable solid. This view largely ignores the impact on safety of adding lithium metal, which exothermically reacts with water to evolve hydrogen gas. This potential safety consideration as well as others from a fault tree analysis of LMSSB will be introduced and explored.
Batteryarchive.Org – Insights from a Public Repository for Visualization, Analysis, and Comparison of Battery Data across Institutions
Authors: De Angelis Valerio , Preger Yuliya
Published: July 2021

The availability of raw battery data in a standard format is critical for the evaluation of experimental studies across institutions and for the development of more accurate performance and degradation models. In this presentation, we will describe the design of BatteryArchive.org, a public database with standardized metadata and file formats, and visualization of all uploaded times series and cycle data. We will discuss the open source tools used to develop the database, web application, and data manipulation features. We will present the insights gained from a broad assessment of recently uploaded data from an array of institutions and show how the site can be used in conjunction with other open source tools for battery data processing, such as BEEP and PyBaMM. The site was launched with cycling data for commercial Li-ion cells, but we envision expanding to other kinds of battery data in the future. We welcome critical feedback on the current site and collaboration on the development of new features.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2020-14192 A
Electrochemical-Thermal Effect on Lithium Plating and Cell Failure
Authors: Perumaram Rangarajan Sobana , Mukherjee Partha P. , Barsukov Yevgen
Published: July 2021

Lithium plating is a detrimental process occurring in the anode of lithium-ion batteries. Plating usually occurs when the rate of incoming lithium flux exceeds the rate of intercalation at the graphite anode. Research over the past years have identified common triggers for lithium plating as low temperature, high rate charging and high states of charge due to reduced lithium ion diffusivity or increased charge transfer resistance in these conditions. One common method proposed to overcome the reduced diffusivity issues is high temperature charging. In this study, pouch cells were cycled at different temperatures to see how plating evolves with aging. Although, cells cycled at high temperature show minimal plating in the beginning of cycling, increasing amounts of plating is observed in the cell with cycling. Although operating at high temperatures aids with the diffusion of lithium ions other secondary aging mechanisms such as the solid electrolyte interphase (SEI) growth and passivation of plated lithium are accelerated leading to cell failure. A combination of electrochemical and material characterization methods is employed to identify the operational interplay of temperature and plating using three-electrode pouch cells. Operando anode potential measurements were used to identify whether lithium plating is the cause or consequence of cell failure.
A Thermodynamically Consistent Variational Framework to Model Lithium Nucleation and Subsequent Plating Under Fast Charge Conditions
Authors: Karra Suryanarayana , Allu Srikanth
Published: July 2021

Based on US Department of Energy’s stated goal for extreme fast charging the electric vehicle batteries need to charge in 10-15 min, which requires drastic improvement upon existing state-of-the-art batteries. One of the primary challenges under fast charge conditions is the lithium plating on graphite anode, which severely degrades the performance and cycle life. Further, the plated lithium grows as dendrites often result in a catastrophic failure. A variational phase field formulation has been developed, which enables to initiate the nucleation of lithium particles based on the local plating overpotential conditions and further allowing to predict the lithium plating under fast charge conditions. In this work we demonstrate that at small charging current density, there is no nucleation and plating of metallic lithium, and no effect on the intercalation kinetics. But from intermediate to fast charging current densities, a stagnated growth from isolated lithium nuclei is observed followed by growth into large nuclei and a continuous growth of metallic lithium. The formulation sets the stage for predicting and evaluating the influence of various electrolyte compositions, graphite particle morphologies and electrode loadings on the nucleation and plating dynamics under fast charge conditions.
Understanding the Graphite Anode Electrode Failure Mode in Cycled Commercial Lithium-Ion Batteries
Authors: Liu Gao
Published: July 2021

The structure degradation of commercial Lithium-ion battery (LIB) graphite anodes was investigated and reported here. The first was to investigate the electrode degradation by examining the PVDF binder degradation after extended cycling. We concluded that the PVDF binder is extremely stable and has no structure degradation after 800 cycles. The graphite materials with different cycling numbers and charge rates was investigated by focused ion beam (FIB) and scanning electron microscopy (SEM). The cross-section image of graphite anode by FIB milling shows that cracks, resulted in the volume expansion of graphite electrode during long-term cycling, were formed in parallel with the current collector. The crack occurs in the bulk of graphite particles near the lithium insertion surface, which might derive from the stress induced during lithiation and de-lithiation cycles. Subsequently, crack takes place along grain boundaries of the polycrystalline graphite, but only in the direction parallel with the current collector. Furthermore, fast charge graphite electrodes are more prone to form cracks since the tensile strength of graphite is more likely to be surpassed at higher charge rates. Therefore, for LIBs long-term or high charge rate applications, the tensile strength of graphite anode should be considered.
Stresses in Porous Electrodes with Particle-Particle Contact and Binder Influence
Authors: Wu Yang , Guo Zhan sheng
Published: July 2021

Particle fracture and particle-binder interface debonding caused by stress will induce the performance deterioration of Li-ion battery porous electrodes. Here we developed a model to systematically investigated the effect of direct particle-particle contact and the effect of binder on stress evolution. The stress in active particle with only particle contact, with only binder contact and with both contacts were numerically studied. The influence of particle size, lithium flux at the particle–binder interface, the binder elastic modulus, and binder coverage ratio on the stress development and particle-binder interface debonding were explored. The numerical study indicates that there is significant stress in the area of direct contact between particles. Moreover, the interfacial debonding decreases with the increasing of particle size and C-rate, and with the decreasing of binder elastic modulus. The optimized binder coverage ratio was obtained. This work provides guidance for optimizing battery performance by rationally designing parameters in porous electrodes.
Role of High-Temperature Separator Stability on Safety and Thermal Signature of Li-Ion Pouch Cells
Authors: Zhou Hanwei , Parmananda Mukul , Fear Conner , Mukherjee Partha P.
Published: July 2021

Thermal safety hazards are a bottleneck problem that constrains the development of lithium-ion batteries with high energy density. Although the internal short circuit (ISC) caused by separator rupture has been identified as a primary driver of catastrophic failure, the effects of separator architecture and high-temperature robustness on thermal runaway behaviors still need fundamental understanding. This study investigates custom-built pouch cells assembled with a wide range of separators to understand the impact of separators on cell-level thermal stability and resistance to catastrophic ISC. Carefully designed thermal abuse tests reveal how the separator shrinkage, melting, and collapse correlate with micro and massive ISC to drive the unstoppable thermal runaway. Cells are subjected to extreme operating conditions to facilitate quantification of the role of separator characteristics on the thermal runaway signature. The implications of separator distinctions on modulating chemical crosstalk between anode and cathode are explored to determine the dominant mechanism that triggers the onset of thermal runaway, with mitigation strategies being proposed from a new perspective.
The Role of Cobalt and Manganese for the Safety of Ni-Rich NMC Cathode
Authors: LIU Xiang , Xu Guiliang , Yin Liang , Hwang Inhui , Ouyang Minggao , Amine Khalil
Published: July 2021

The intrinsic poor thermal stability of layered LiNi
x
Co
y
Mn1–x–y
O2 (NCM) cathodes and the exothermic side reactions triggered by the associated oxygen release are the main safety threats for their large-scale implantation. In the NCM family, it is widely accepted that Ni is the stability troublemaker, while Mn has long been considered as a structure stabilizer, whereas the role of Co remains elusive. Here, via Co/Mn exchange in a Ni-rich LiNi0.83Co0.11Mn0.06O2 cathode, we demonstrate that the chemical and structural stability of the deep delithiated NCM cathodes are significantly dominated by Co rather than the widely reported Mn. Operando synchrotron X-ray characterization coupling with in situ mass spectrometry reveal that the Co4+ reduces prior to the reduction of Ni4+ and could thus prolong the Ni migration by occupying the tetrahedra sites and, hence, postpone the oxygen release and thermal failure. In contrast, the Mn itself is stable, but barely stabilizes the Ni4+. Our results highlight the importance of evaluating the intrinsic role of compositional tuning on the Ni-rich/Co-free layered oxide cathode materials to guarantee the safe operation of high-energy Li-ion batteries.
Development of Cu/F-MWCNT/ZnO Based Active Layer for Long Term Soil Urea Measurements
Authors: S K Naveen Kumar , A Akshaya Kumar , Baburaj Aiswarya , Fernandez Renny Edwin , Khosla Ajit
Published: July 2021

There is a significant interest in the detection of nutrient levels in smart agriculture farms. In this paper, we report the development of Zinc oxide (ZnO) modified multi-walled Carbon nanotube (F-MWCNT) nanocomposite thin film layers specifically for soil nitrogenous fertilizers level detection. The nanostructured ZnO loaded over the surface of F-MWCNT forms the nanocomposite active layer. The surface morphology of the F-MWCNT/ZnO is characterized using field emission scanning electron microscopy (FeSEM) and energy-dispersive X-ray spectroscopy (EDS). Crystal phase and orientation of F-MWCNT, ZnO and F-MWCNT/ZnO nanocomposites were examined using an X-ray diffractometer (XRD). The electrochemical sensing characteristics of the Cu/F-MWCNT/ZnO structure was measured using an impedance/gain phase analyzing system and resulting composite structure was found to have a proportional impedance change with soil Urea levels. The performance of the sensor was investigated in the 1- 10 kHz range. The impedance magnitude was found to be a linearly decrease with the Urea levels.
(Keynote) Blood, Sweat and Tears... – Sensing of Human Performance Biomarkers in Bodily Fluids Using Point-of-Use Devices
Authors: Steckl Andrew
Published: July 2021

Hormones produced by glands in the endocrine system and neurotransmitters produced by the nervous system control many bodily functions. The concentrations of these molecules in the body are an indication of its state, hence the use of the term biomarker. Excess concentrations of biomarkers, such as cortisol, serotonin, epinephrine, dopamine, are released by the body in response to a variety of conditions - emotional state (euphoria, stress), disease, etc. The development of simple, low-cost modalities for point-of-use (PoU) measurements of biomarkers levels in various bodily fluids (blood, urine, sweat, saliva) as opposed to conventional hospital or lab settings is receiving increasing attention. The presentation starts with a review of the basic properties of primary stress-related biomarkers: origin in the body (i.e. if they are produced as hormones, neurotransmitters or both), chemical composition, molecular weight (small/medium size molecules and polymers, ranging from ~100Da to ~100kDa), hydro- or lipo-philic nature. Next, a review of the published literature is presented regarding the concentration of these biomarkers found in several bodily fluids that can serve as the medium for determination of the condition of the subject: blood, urine, saliva, sweat and, to a lesser degree, interstitial tissue fluid. The concentration of various biomarkers in most fluids covers a range of 5-6 orders of magnitude, from 100s of ng/mL (~1µM) down to a few pg/mL (sub 1pM). Mechanisms and materials for point-of-use biomarker sensors are summarized and key properties are reviewed. Illustrative examples from the literature are discussed for several sensor device categories, including lateral flow (immuno)assay devices and microfluidic devices. Selected methods for detecting these biomarkers are reviewed, including antibody- and aptamer-based colorimetric assays, electrochemical and optical detection. Finally, the presentation outlines key challenges of the field and provides a look ahead to future prospects.

A. J. Steckl and P. Ray, “A Review of Stress Biomarkers Concentrations in Bodily Fluids and Their Point-of-Use Detection”, ACS Sensors, 3 (10), 2025-2044, Sept 2018 (10.1021/acssensors.8b00726)

V. Venkatraman and A. J. Steckl, “Quantitative Detection in Lateral Flow Immunoassay Using Integrated Organic Optoelectronics”, IEEE Sensors, 17 (24), 8343, Dec 2017 (10.1109/JSEN.2017.2764178 ).

P. Ray and A. J. Steckl, “Label-Free Optical Detection of Multiple Stress Biomarkers in Sweat, Plasma, Urine and Saliva”, ACS Sensors
4, 2019. (10.1021/acssensors.9b00301)

S. Dalirirad and A. J. Steckl, “Aptamer-Based Lateral Flow Assay for Point of Care Cortisol Detection in Sweat”, Sensors & Actuators
283, 79-86, Jan 2019 (https://doi.org/10.1016/j.snb.2018.11.161).

Figure 1
Antibody Nanopatterned Biosensor for Detection of Physical Confinement-Induced Cytokine Secretion in Breast Cancer
Authors: Zhou Zhiru , Cui Feiyun , Zhou Hong
Published: July 2021

Physical confinement have been shown to alter cancer cell migration mechanisms and regulate intracellular signaling events during tumor development and metastasis. However, the effect of confinement on cytokine secretion remains largely unknown. To better understand this, we designed an in-vitro confinement environment with cell vertically confined and sandwiched between two collagen coated glass slides. This method can enable vertical confinement down to 5. Human epithelial cell MCF10A and breast cancer cell MDA-MB-231 were then cultured inside the in-vitro vertical confinement chamber for 48h. Using PCR test, we found that IL-6 expression was largely upregulated in MDA-MB 231 cell line after vertical confinement. We then designed and fabricated a nanopatterned electrochemical immunosensor to determine the IL-6 level in cell culture serum after confinement. The immunosensor was constructed by employing Au nanopatterned surface immobilized with antibody, exhibited a low limit of detection. The obtained results point towards rapid, sensitive, and specific early diagnosis of breast cancer at the point of care and other low-resource settings.
Conductive Polymers Modification for Carbon Fiber and Platinum Microelectrodes for the Measurement of Neuropeptide Y
Authors: Lozano Kelly , Lopez Luis F. , Cunci Lisandro
Published: July 2021

Currently, one of the approaches in neuroscience research is the analysis and understanding of neurochemical behaviors. This is a great challenge since, although neurotransmitter measurements have been possible, these techniques have limitations, among which are the selectivity, sensitivity, and temporal resolution of the measurement. This work seeks to improve the Electrochemical Impedance Spectroscopy (EIS) technique using a Carbon Fiber Microelectrode and a Platinum Microelectrode for measurement with a conductive polymer modification of Pyrrole and Aniline. The EIS technique allows the measurement of the interaction of molecules in a solution and the surface of the electrode. The modification with conductive polymer is carried out since it is biocompatible, and having a load causes the selectivity to increase and, in turn, its sensitivity, in addition to being modifiable according to the application. Our objective is to find the optimal conditions for the modification of the surface of the microelectrode with the conductive polymers for use with EIS by measuring different neurotransmitters to study and understand its release mechanism and then be able to measure different concentrations. Our neuropeptide of interest is Neuropeptide Y (NPY) because it is related with many processes in the human body as regulation of appetite, stress, and diseases as Alzheimer and Parkinson disease. For conductive polymer modification we used 0.5M Pyrrole and Aniline in 0.5M H2SO4. Cyclic Voltammetry (CV) is applied to carry out the electropolimerization with 1 cycle per depositions 3 times. We used two solutions of ACSF (artificial cerebral-spinal fluid) one of them mixed with 10pg/ml of NPY and the other one without NPY to study the current behavior. SEM and EDS were used to study the morphology. As results for ACSF and ACSF-NPY we observed an increased in current at the first electropolymerization and a decreased after the second electropolymerization for CV.
In Brain and in Vein Detection of Antibiotics Using Electrochemical-DNA Biosensors
Authors: Dauphin Ducharme Philippe
Published: July 2021

Current approaches towards drug dosing rely on venous draws measurements performed on test patients which are laboratory-analyzed and returned the following days. This practice forces physicians to administer potentially toxic or ineffective concentrations of drugs to patients since dosages are determined based on weight and age of this test group even though pharmacokinetics may differ in each individuals. Having a technology that would in contrast allow, direct, continuous, real-time monitoring of drugs in the living body would revolutionize healthcare and allow personalized drug dosage and adjustment while enabling the development of artificial organs responsible of adjusting these levels.

Motivated by this goal, we have developed a class of electrochemical aptamer-based (E-AB) sensors[1]. These sensors are comprised of a redox-reporter-modified DNA “probe” that is attached by one terminus to a self-assembled monolayer deposited on an interrogating electrode. The binding of an analyte to this probe alters the kinetics with which electrons exchange to/from the redox reporter via binding-induced conformational changes producing an easily measured change in current when the sensor is interrogated using square-wave voltammetry (see Figure) [2]. E-AB sensors are capable of detecting with high specificity their molecular targets in flowing whole blood and directly in the living body. I will present during this presentation some of these sensors deployed in the vein [3] and in the brain of sedated rats to monitor the pharmacokinetics of the antibiotic, vancomycin. The ability of acquiring high frequency measurements of drug plasma levels using these biosensors has also allowed us to develop a technology that improves our ability to deliver them [3]. Due to their small size, these sensors can also be deployed directly in the brain of freely moving animals to monitor molecules with unmatched temporal resolution [4]. All these advancement in developing E-AB sensors are aimed towards developing new analytical tools for personalized medicine while improving our understanding of drug metabolism.

[1]: Dauphin Ducharme, P. and Plaxco, K. W. Anal. Chem. 2016, 88, 11654–11662.

[2]: Li, H., Dauphin Ducharme, P., Ortega, G., Plaxco, K. W. J Am. Chem. Soc. 2017, 139, 11207-11213.

[3]: Dauphin-Ducharme, P., Yang, K., Arroyo-Currás, N., Ploense, K., Zhang, Y., Gerson, J., Kurnik, M., Kippin, T. E., Stojanovic, M., Plaxco, K. W. ACS Sensors 2019, 4, 2832-2837.

[4]: Ploense, K., Dauphin-Ducharme, P., Arroyo-Currás, N., Williams, S.; Schwarz, N., Kippin, T. E., Plaxco, K. W. 2020 Under review.

Figure 1
(Invited) Exploring in the Near Infrared: Multifunctional Nanoplatforms for Biomedical Applications
Authors: Ma Dongling
Published: July 2021

Near-infrared (NIR) absorbing and emitting nanomaterials attract significant attention in bioimaging, which shows great potential for disease detection due to its high sensitivity at the subcellular level and low cost of related imaging facilities. However, currently available optical probes are mainly based on visible-emitting materials. The tissue-induced optical extinction and autofluorescence in the visible range result in limited penetration depth and ambiguous photoluminescence signal, which restricts their in vivo use. To address this issue, photoluminescent probes, with both absorption and emission wavelengths operating in the biological windows in the NIR range, in which tissues are optically transparent, are highly desired. Their integration with superparamagnetic nanomaterials to make a multifunctional platform further opens a wide range of promising applications, including bimodal imaging (photoluminescence and magnetic resonance imaging), synergistic hyperthermia (magnetothermal and photothermal), magnetic confinement of trace amounts of biospecies for ultra high-sensitivity biodetection, etc. In this talk, I will present our most recent work on the synthesis of NIR-emitting water soluble, stable core/shell/shell quantum dots (QDs) and multifunctional (NIR photoluminescent and superparamagnetic) nanoparticles and their use in biomedicine. For instance, in one case, multifunctional particles contain single superparamagnetic nanoparticles as cores and NIR-luminescent nanomaterials as shells. In another case, the multifunctional nanoplatform is compose of multiple superparamagnetic nanoparticles and NIR quantum dots in single particles. These different types of multifunctional particles are designed for different biomedical applications.

References: [1] ACS Nano 2019, 13, 408-420; [2] Adv. Funct. Mater. 2018, 1706235 (Inside Back Cover); [3] Chem. Mater. 2019, 31, 3201-3210.
Universal Fentanyl Sensor for Strip and Wearable Non-Invasive Testing
Authors: Wang Zhe
Published: July 2021

Current technologies rely on bulkier instruments for detecting small molecule concentration in in the bodyfluids. However, they required time consuming preparation of mixture prior to analysis. In this study, we have demonstrated the new sensing method by using conducting polymer combined with our designed anchor molecule. The sensing interface has secured the ultra-high sensitivity to specific adsorption, which reform the electronic structure of polyaniline substrate by altering the delocalized electrons. Moreover, the PANI structure can be easily tuned for any given sensitivity of detection. Computationally, it was confirmed that the interactions between fentanyl and anchor interface are significantly strong (≈ -1.19 eV). The range of interaction energies is found due to the variation of the positions of key functional groups of fentanyl relative to the PAni-Arg structure. Particularly with strong interactions, spontaneous proton transfer is observed from the sensor to the fentanyl molecule. The sensor showed excellent response when used in different human bodily fluids. In addition to these interactions at the interface, we have demonstrated a new sensing technique as the first type of phase angle detection sensor. Using this technique, the changes at the interface have inherently amplified signals compared to changes in resistance, potential, and/or current signals. The new interface of biocompatible and flexible composite layers can be fabricated via electrochemical approach on variety of surface with minimal maintenance. This approach is particularly useful for assays that requires extremely low sample volume. We showed our designed method and device can be used for testing strip/vial for tear and blood samples and testing patch for in-situ monitoring through skin perspiration. Lastly, electrochemical approach is facile to use, it enables the portability of the sensor for on-site field measurements as well as in clinical settings. This work helped to resolve the challenge of monitoring small molecule drugs accurately and rapidly for point-of-care (POC) diagnosis in current clinical settings.
Capacitive Electrochemical Sensor with Molecularly Imprinted Polymer for Determination of Heterocyclic Aromatic Amines
Authors: Ayerdurai Viknasvarri , Garcia-Cruz Alvaro , Cieplak Maciej , Sharma Piyush Sindhu , D'Souza Francis , Kutner Wlodzimierz
Published: July 2021

Quinoxaline heterocyclic aromatic amines (HAAs), are formed during meat and fish cooking, frying, or grilling at high temperatures. HAAs are classified as potent hazardous carcinogens, even though the HAAs are usually generated at very low concentrations (~ng per g of a food sample). This is because the HAA food contaminants effectively damage DNA by intercalation or strand break. Hence, chronic exposure to HAAs, even in low doses, can cause cancers of the lung, stomach, breast, etc. Currently, HPLC is used for the determination of these toxins in food matrices. However, this technique is expensive, tedious, and time-consuming. Therefore, fast, simple, inexpensive, and reliable HAAs determination procedures, without the need for separation of these toxins, in the protein food matrices are in demand. Molecularly imprinted polymers (MIPs) are excellent examples of bio-mimicking recognition materials. Therefore, they have found numerous applications in selective chemosensing. Within the present project, we synthesized a nucleobase-functionalized molecularly imprinted polymer (MIP) as the recognition unit of an electrochemical sensor for selective DPV and capacitive detection and determination of 2-amino-3,7,8-trimethyl-3H-imidazo[4,5-f]quinoxaline (7,8-DiMeIQx) HAA. MIP-(7,8-DiMeIQx) film-coated electrodes were sensitive and selective to 7,8-DiMeIQx. The linear dynamic concentration range of the devised chemosensor extended from 12 µM to 0.4 mM 7,8-DiMeIQx and the imprinting factor was high, IF = 13.

The present work is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 711859. Scientific work was funded from the financial resources for science in the years 2017-2021 awarded by the Polish Ministry of Science and Higher Education for the implementation of an international co-financed project and National Science Centre Poland (grant No. NCN 2014/15/B/NZ7/01011 to W.K.)
Fabrication of Electrochemical Biosensor for Detection of Full-Length Tau Protein through Biotin-Streptavidin on Gold Surface
Authors: Wallace William , Martic Sanela
Published: July 2021

Tau is a neuronal protein responsible for microtubule formation [1]. It is also the pathological protein active in the Alzheimer’s Disease (AD) pathway. When Tau begins to aggregate as a result of misfolding, the neuronal cells die due to the lack of microtubule formation and can take on prion-like properties [2]. Therefore, detection of aggregated Tau can serve as a powerful tool in the early diagnosis of AD and dementia related diseases. As has been previously demonstrated, Tau 441 can be detected with an electrochemical immunoassay based on the electrochemical impedance spectroscopy (EIS) by using gold electrode [3]. The EIS was also used to monitor interactions between Tau protein and Heparin [4]. Herein, we describe use of EIS to monitor and detect Tau and its aggregates by using gold electrode modified to include a biotinylated aptamer to tau and streptavidin-Au sensor through a series of surface modifications. Surface modifications were characterized using EIS and CV. After modifying the surface of the electrode, the detection of Tau was achieved using EIS. Aggregation of tau was also monitored as a function of Tau or Heparin concentrations, and incubation time and temperature. The control experiments included, Tau-free surface, Heparin-free solution, buffer solution in order to minimize aggregation. The charge transfer resistance, Rct, was determined by fitting the experimental data to the equivalent circuit. The Rct values for Tau-films on gold surface were compared prior and post aggregation. The Rct values were highly dependent on the experimental conditions. Data indicate that this electrochemical sensor holds great promise for detection of neurodegenerative biomarkers which undergo aggregation.

References

[1] M.D. Weingarten, A.H. Lockwood, S. Hwo, M.W. Kirschner, A Protein Factor Essential for Microtubule Assembly, Natl. Acad Sci. 72 (1975) 1858–1862.

[2] F. Clavaguera, J. Hench, M. Goedert, M. Tolnay, Invited review: Prion-like transmission and spreading of tau pathology, Neuropathol. Appl. Neurobiol. 41 (2015) 47–58.

[3] N. Carlin, S. Martic-Milne, Anti-tau antibodies based electrochemical sensor for detection of tau protein biomarkers, J. Electrochem. Soc. 165 (2018) G3018–G3025.

[4] H. Trzeciakiewicz, J. Esteves-Villanueva, R. Soudy, K. Kaur, S. Martic-Milne, Electrochemical characterization of protein adsorption onto YNGRT-Au and VLGXE-Au surfaces, Sensors (Switzerland). 15 (2015) 19429–19442.
Quantification of Protease Activity Using a Multiplex Microelectrode Array Sensor
Authors: Anderson Morgan J , Song Yang , Fan Huafang , Wright Jestin Gage , Ren Zhaoyang , Hua Duy H , Koehne Jessica E. , Meyyappan Meyya , Li Jun
Published: July 2021

Proteases are a class of enzymes responsible for selectively breaking down proteins and thus they are involved in many biological processes ranging from apoptosis to hormone regulation. Overexpression of proteases is often indicative of several health conditions, such as muscle atrophy, bone loss and cancer progression. Consequently, the measurement of protease activity can serve as a biomarker for diagnosis as well as the efficacy of treatment regimens. Developing rapid low-cost techniques that can quantitatively detect multiple proteases is essential for these applications.

Here we show the electrochemical characterization of a microfabricated sensor consisting of nine individually addressable microelectrodes. Subsequently, we demonstrate the application of this microelectrode array for the simultaneous, multiplex detection and quantification of protease activity. To accomplish this, each electrode is functionalized with a specific ferrocene labelled hexapeptide substrate and the electrochemical signal is monitored by AC voltammetry. In the presence of the target protease, the AC voltammetry signal decays as the target protease cleaves the peptide substrate, causing the ferrocene tags to leave the electrode surface. The proteolytic activity is determined by fitting the decay in signal to an exponential curve in accordance with the Michaelis-Menten model of heterogeneous kinetics. Our results show that each electrode of the MEA can be selectively modified with little or no contamination from adjacent electrodes. Additionally, we demonstrate that three different peptide substrates can be simultaneously used to quantify the protease activity of a sample. This microelectrode array sensor will be used to develop a portable instrument to track muscular atrophy progression during long duration space habitation in microgravity and to evaluate potential physiological and pharmaceutical countermeasures.
pH and Temperature Sensor Platform for Detecting Inflammation at Specific Sites in the Oral Cavity
Authors: Ritzert Nicole L , Kim Shinae , Rani Asha , Moffat Thomas
Published: July 2021

Our goal is to make electrochemical sensors for measuring oral fluids and tissues to aid in more accurate diagnosis and monitoring of oral diseases. In this work, we developed a sensor platform capable of measuring simultaneously pH and temperature for detecting inflammation at specific sites in the mouth. Miniaturized, planar pH sensing and reference electrodes were combined on a flexible polymer platform along with a platinum resistance temperature detector (RTD) using a combination of microfabrication and electrodeposition techniques. The resistance of the platinum RTD was linear between 20 and 60 °C, with a precision of ±0.1 °C. The pH response and reproducibility of sputtered iridium oxide (IrOx) was compared with those of electrochemically deposited IrOx. The voltage of the pH sensor was measured in solutions of varying pH, chloride concentration, and temperature mimicking the oral environment. At room temperature, sputtered IrOx sensors exhibited a linear response (-47 to -55 mV/pH) for pH 2-10 whereas electrodeposited IrOx was linear (-72 to -82 mV/pH) over pH 4-8, which is within the range expected in the oral cavity. The sensitivity of the sputtered IrOx was more reproducible between individual sensors than electrochemically deposited IrOx; however, sputtered IrOx electrodes were more difficult to fabricate and had a lower sensitivity to pH. Voltage stabilized (within 1-2 mV) in 10-120 s and reached 90 % of this stable value within 5 s at each pH value. The electrodeposited Ag/AgCl reference responded linearly to [Cl-] as well asvaried by <2 mV over pH 4-8. Repetitions of reproducible sensors at one pH were ≈0.1 pH unit. Preliminary measurements indicated that pH sensitivity of the IrOx sensors was ≈0.1 mV/pH/°C, producing an apparent change of ≈0.2 pH between room temperature (21 °C) and the mouth (35 °C); therefore, the voltage will need to be calibrated based on temperature.
UV-Ozone Treated Modified Laser-Induced Graphene Based Electrochemical Sweat Sensor
Authors: Choudhury Sudipta , Bhattacharya Gourav , Sinha Roy Susanta
Published: July 2021

Recent studies shows laser-induced graphene (LIG) based electrodes can be very effective for electrochemical sensing applications. In this work, we aim to develop a stable ion selective membrane (ISM) based sweat sensor using laser-induced graphene (LIG) as the electrode material. However, the surface of pristine LIG is hydrophobic. Hence, coating these hydrophobic LIG films with ISM produces low sensitivity in sensing applications. In this study, UV-Ozone irradiated laser-induced graphene (LIG) based electrodes were explored for sensing biomarkers like ion in sweat. Solid-state ion-selective electrodes (ISEs) sensitive to ions were fabricated by a two-step drop-coating process of polyvinyl chloride solution containing plasticizer, ionophore, and ion-exchanger on the LIG electrode. We found the ozone treatment process significantly increased the electrochemical active surface area (EASA) and porosity of the pristine LIG. Hydrophobic to hydrophilic transition induced by UV-Ozone treatment reduced the contact angle (CA), resulting in better permeation of the ion-selective membrane (ISM) into the ozonized LIG film. Raman spectroscopy and IR absorption studies indicate physisorption of ozone on LIG. The concentration of the ISM solution has a great influence on attachment to the O-LIG film. Here, we report the applicability of O-LIG as an electrochemical sensor towards the detection of sodium ion () using the open circuit potential (OCP) method. The performance of ozonized LIG (O-LIG) electrodes was much better than pristine LIG and screen printed carbon electrodes. The sensitivity of 60.2 ± 0.9 mV/ decade to Na+ ions and a lower limit of detection of 1 × 10-6 M was achieved using O-LIG based ISEs. Response time of the O-LIG based electrodes were around 1 min. The current study demonstrates that the LIG-based electrodes can be used as a flexible electrochemical sensing platform and is suitable for future wearable sensing devices.

Keywords

Laser-induced graphene; ion-selective electrode; wearable sensors; electrochemical sensor; sweat sensor.
Interdigitated Electrode Arrays for Electrochemical Immunosensing of Interleukin-6 in Cerebrospinal Fluid (CSF) and Serum
Authors: Oh Christiana , Yang Liu , Park Bumjun , Bohn Paul
Published: July 2021

Electrochemical immunosensors combine the advantages of electrochemical transducers such as low cost, potential for miniaturization, and quantified readout with the selective properties of immunochemical recognition elements. Here we describe a simple, label-free electrochemical immunosensor for the rapid detection of traumatic brain injury (TBI) by quanitifcation of a cytokine interleukin-6 (IL-6) in cerebrospinal fluid (CSF). The sensor system consists of gold interdigitated electrode arrays (IDEAs) that are modified with self-assembled monolayers (SAMs) and IL-6 antibodies (IL-6 mAb) for antigen recognition and capture. Electrode modification was confirmed using surface characterization (FT-IR, fluorescence) and electrochemically via EIS. The sensor performance was evaluated in IL-6 spiked PBS solution: the LOD was determined to be 1.63 pg/mL, with a linear range across 4 orders of magnitude. The sensor exhibits selectivity against non-target cytokines TNF-α and IL-10. The detection of CSF and serum IL-6 using the outlined system will be discussed for use as a point-of-care (POC) diagnostic and prognostic tool for TBI.
(Invited) SERS-Based Paper Lateral Flow Assays for Point-of-Care Testing
Authors: Wu Nianqiang Nick
Published: July 2021

First, surface-enhanced Raman scattering (SERS) probes have been developed. Subsequently, SERS probes have been coupled to a nano-array to form chip-based enzyme-linked immunosorbent assays (ELISA). Next, the SERS probes and ELISA have been integrated into paper-based microfluidic strips to form an automated and miniaturized optofluidic device for point-of-care testing.
Electrodeposition of Gold Nanoparticles on Halloysite Nanotubes Modified Glassy Carbon Electrode for Detection of Dopamine and Serotonin
Authors: Prasad Sai Prasad , Ramamurthy Sai Sathish , Kumar J K Kiran
Published: July 2021

We report a novel nanocomposite composed of halloysite nanotubes (HNT) and gold nanoparticles (AuNPs) as an excellent sensing platform. Electrodeposition of AuNPs was carried out by cyclic voltammetry for 120 seconds on HNT/GCE in acidic medium to form Au/HNT/GCE. The nanocomposite was characterized by UV-visible spectroscopy and Scanning Electron Microscopy. Higher surface area was created by drop casting HNT which helped in adhering high number of AuNPs that gave rise to enhanced catalytic sites. The modified electrode was used to simultaneously detect dopamine (DA) and serotonin (SE) at nanomolar concentrations. Oxidation peaks of DA and SE was found at 0.3 V and 0.6 V adapting the differential pulse voltammetry. The limit of detection was calculated to be 9.7 × 10-6 M and 92 × 10-9 M for DA and SE respectively with S/N=3. The modified electrode exhibited high sensitivity and stability towards detection of DA and SE.
Response of TiO2-MnO2 Based Sensor to Human Urine Odour
Authors: Mohiuddin Ilyas , Khalid Mubashir uz Zafar Mohammed
Published: July 2021

A new composite mixed metal oxide TiO2-MnO2 based thick film sensor fabricated with high sensitivity to diseased human urine odour by simple solid-state method. The maximum sensitivity 0.95 obtained at an applied voltage of 1.8v for diseased human urine odour.

Figure 1
In Vivo Monitoring of Neurotransmitters in Alive Zebrafish (Danio rerio) Embryos
Authors: Deshpande Aaditya , Dumitrescu Eduard , Orr Cassandra , Wallace Kenneth , Andreescu Emanuela
Published: July 2021

The important biological pathways inside our body are controlled by neurotransmitters. Their real time measurements are always a challenge due to the high reactivity, low concentrations and short lifetime. The use of electrochemical sensors for such type of measurement is well established. Herein we show the in vivo measurement of Serotonin and Nitric Oxide inside Zebrafish embryos. We developed custom made carbon fibre microelectrodes which are inserted in the embryos for real time measurement. The embryos were exposed to metal nanoparticles (Cu, CuO and CeO2) to stimulate the Inflammatory Bowel Disease onset and the neurotransmitter concentrations were measured to study their impact on the pathway expression.
Metal-Organic Framework and Silver Nanowire Composites As Chemiresistive Gas Sensors Operating at the Percolation Threshold
Authors: Lister Abigail Mary , Armitage Ben I. , Wang Yu , Lefferts Merel J. , Castell Martin R.
Published: July 2021

The high internal service areas and consequent high numbers of sites for analyte adsorption of Metal-Organic Frameworks, MOFs, make them attractive candidates for gas sensing applications. Through synthesis of conductive MOFs we present a novel way of fabricating chemiresistive sensors able to detect NO2 gas in the low ppm range. A suspension of MOF and Ag nanowires in solution is prepared and drop cast onto paper to form the sensing medium. Sufficient conductive MOF is added to an insulating concentration of nanowires to give a conductive sample operating in the percolation region. The percolation region refers to the point before a thin film has formed where a small change in the number of conductive pathways leads to the largest change in material conductivity, as depicted in figure 1.1 By fabricating sensors operating in this region, a small interruption in the conductive network due to analyte interaction leads to a large change in measurable conductivity, allowing higher sensor sensitivities to be accessed.2
,
3 Moreover, the use of MOFs lends itself to the systematic synthesis of sensing media tailored to respond to desired gaseous analytes. Through selection of organic linkers with particular functional groups and/or particular metal nodes, the functionality and pore sizes of the resulting MOFs can be manipulated. We have synthesised MOFs with Cu, Ni and Fe metal centres linked by hexahydroxytriphenylene ligands4 and fabricated chemiresistive sensors through combination with Ag nanowires. Their different sensing responses to NO2 and NH3 gases with concentrations below 5 ppm have been recorded, and the simultaneous exposure of all three MOF sensors in an array to gaseous analytes is anticipated to further increase sensor selectivity.

Figure 1: Schematic of a percolation curve, demonstrating how the conductivity between two electrodes changes as the concentration of conductive material, such as conductive polymer, between the electrodes is increased. The optimum region for sensing experiments is where the gradient is steepest; the percolation region. Image reproduced from reference 1.

References

Murugappan K, Castell MR. Bridging electrode gaps with conducting polymers around the electrical percolation threshold. Electrochem commun. 2018;87:40-43. doi:10.1016/j.elecom.2017.12.019

Lefferts MJ, Murugappan K, Wu C, Castell MR. Electrical percolation through a discontinuous Au nanoparticle film. Appl Phys Lett. 2018;112(25):251602. doi:10.1063/1.5023163

Armitage BI, Murugappan K, Lefferts MJ, Cowsik A, Castell MR. Conducting polymer percolation gas sensor on a flexible substrate. J Mater Chem C. 2020;8:12669. doi:10.1039/d0tc02856h

Campbell MG, Liu SF, Swager TM, Dincə M. Chemiresistive Sensor Arrays from Conductive 2D Metal-Organic Frameworks. J Am Chem Soc. 2015;137(43):13780-13783. doi:10.1021/jacs.5b09600

Figure 1